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Voiland College of Engineering and Architecture School of Mechanical and Materials Engineering

MME Seminar Series Welcomes: Daicheng Fu, SEL Pullman

11:00 – 12:00 noon in ETRL 101

Refreshments served in ETRL 119 at 10:30 am

Daicheng Fu

Process Engineering Operations ManagerSchweitzer Engineering Laboratories

Abstract

This study is to evaluate different process combinations to solder Pb-free BGA under SnPb solder environment. Four variables are included in the full factorial experiment design, PCB finish type, paste/flux type, BGA ball composition and BGA package type. An elevated temperature reflow profile is used for all test groups. Thermal cycling and board bending tests are performed.

Results show when HASL finish is used, all mixed soldered Pb-free BGA with SnPb solder paste are able to sustain at least 1,000 thermal cycles. There are early failures before 100 cycles, they are all from ENIG finish boards. The cause of early failures is insufficient formation of inter-metallic compound on the interface between ENIG finish and mass solder. Board bending test also shows much higher percentage of open circuits on ENIG finishing boards.

This study finds the best process combination for Pb-free BGA is HASL finish with PBGA packages. SnPb paste or flux-only does not make significant difference. CSP type packages and low Ag content Pb-free alloy are generally less reliable than PBGA package with SAC305/405 alloy, but as long as HASL finish boards are used, there are no early thermal cycle failures.

 

Biography

Daicheng Fu is a Process Engineering Operations Manager with Schweitzer Engineering Laboratories in Pullman, WA. He received his M.S in Industrial Engineering from Arizona State University and B.S in Mechanical Engineering from Shanghai Jiao Tong University. He has over twenty years of experience in electronics manufacturing, in both consumer   electronics and high-reliability industrial control equipment. In SEL, Daicheng Fu has led several in-depth studies on quality and reliability issues, such as backward-compatibility issue with lead-free components in tin-lead soldering environment; component latent damage caused by board bending stress; tin whisker issue and prevention on lead-free components; and silver dendrite issue and prevention. Currently Daicheng Fu is leading SEL’s process engineering team in new process development; soldering material evaluation; New Product Introduction; and Design for Manufacturability improvement.

 

MME Seminar Series Welcomes Dr. Xiao-Ying Yu, Pacific Northwest National Laboratory

Held in ETRL 101

Refreshments served in ETRL 119 at 10:30 am

Dr. Xiao-Ying Yu

Earth and Biological Sciences Directorate, PNNL

Chemical Mapping of the Evolving Material Interface in Liquids

Abstract

A vacuum compatible microfluidic reactor, SALVI (System for Analysis at the Liquid Vacuum Interface) was employed to study the evolving material interface of particles in liquids.  Three case studies will be provided in this talk.  The first study is a model switchable ionic liquid (SWIL) system consisting of 1,8-diazabicycloundec-7-ene (DBU) and 1-hexanol. When CO2 gas is added to the DBU and 1-hexanol mixture, the solvent polarity is known to change. A series of ionic liquids with different CO2 loading was analyzed. Spatial chemical differences were observed within the same ionic liquid, indicating  Inhomogeneity of the ionic liquid. Spectral principal component analysis (PCA) was conducted. Clear distinctions were   observed among SWILs with different CO2 loadings. The loading plots strongly indicate that fully loaded SWILs share similar spectral components as those of the non-loaded ILs. This finding confirms the      hypothesis of the biphasic structure in the fully loaded IL   predicated by molecular dynamic simulation and presents the first physical evidence of the liquid microenvironment of IL determined by liquid ToF-SIMS. Second, we           investigated the chemical structural evolution of the metal organic framework (MOF) formed over different lengths of times using in situ liquid SIMS imaging.  Zn-MOF-74 is the model system.  Zn-acetate is the metal center and DHTA is the ligand linker in a DMF solvent.  MOFs in solvent are analyzed to ascertain the growth mechanism and the   evolution of the MOF structure.  Ex situ XRD, HeIM, and TEM are used to     characterize MOFs to complement the in situ analysis.  MOF surface area measurement and adsorption and desorption testing illustrate that the MOF pore size    becomes smaller over time yet the overall adsorption/desorption properties  mprove due to the increased density of the pores.  Lastly, large colloidal boehmite particles of importance in nuclear engineering and   processing are studied under a variety of pH conditions.  Particle morphological changes are observed using in situ liquid SEM.  Moreover, the solvent and solute compositions are found to relate to the pH conditions, providing direct evidence of the solvation effect via submicron chemical mapping.  The vacuum compatible microchannel in SALVI offers an    Innovative perspective to study the evolving liquid-liquid and solid-liquid   interface.  This approach allows direct visualization of the spatial and chemical heterogeneity in complex liquids by dynamic ToF-SIMS complemented with other imaging and spectroscopy techniques and provides new insights for improved understanding of the evolving material interface.

Biography

Dr. Yu was trained as a physical chemist and kineticist at the University of Michigan, Ann Arbor, MI. She did her postdoctoral research at Brookhaven National Laboratory and Colorado State University.  She has been a senior scientist at Pacific Northwest National Laboratory since 2006.  She has led the development of a novel mesoscale imaging tool based on microfluidics at PNNL since 2009, which has resulted in three patents, a prestigious R&D 100 award, and a Federal Laboratory Consortium Technology Transfer Excellence Award.  She has developed new concepts in aerosol sampling, led and participated in many field studies for in situ      measurements of aerosols.  Dr. Yu is the chair of the DOE chemical exposure working group; and leads the development of the chemical mixture methodology (CMM) for consequence assessment of toxic health effects since 2008.  She was a member to the DOE Temporary Emergency Exposure Limit (TEEL) Advisory Group (TAG).  Her recent research focuses on in situ mesoscale chemical imaging of soft materials in atmospheric, biology, energy, and material  sciences using microfluidics.

 

 

MME Seminar Series Welcomes Dr. Subhanshu Gupta, WSU EECS

Dr. Subhanshu Gupta, Assistant Professor

Washington State University
School of Electrical Engineering and Computer Science

 

Held in ETRL , Refreshments served in ETRL 119 at 10:30 am

Persistent Sensing using ultra-low-power sub-cubic-millimeter devices for Biosensor Interfaces and Heterogeneous Networks

Abstract

Ubiquitous sensor arrays in ecosystems surrounding us have created an interesting conundrum, i.e. the design of these ecosystems and for that matter even electronic circuits for the worst-case variations have resulted in huge cost overruns and inefficiencies with economy-of-scale. This talk will focus on two systems currently being researched at Systems-On-Chip (SoC) Lab at Washington State University that enables efficient integration and implementation of multi-sensor arrays. The first system will describe a multi-channel sensor array for human vital signs monitoring. A mixture of disruptive technologies from signal processing and information theory, circuit design, nanofibers and additive printing are discussed towards achieving a unified goal of a flexible and reconfigurable vital signs sensor for different biometrics. Applications of sub-Nyquist sampling techniques and additively printed touch sensors for measurement of human electrocardiogram will be demonstrated. The second system will describe a combination of piezo-sensor and radio-frequency phenomenon to capture facial muscular movements in preemies. We will conclude the talk with future directions and open research challenges towards an efficient energy-harvested printed sensor array with integrated RF communications.

Biography

Subhanshu Gupta is a faculty in School of Electrical Engineering and Computer Sciences at Washington State University, Pullman. He received his Ph.D. from the University of Washington, Seattle, WA, USA in 2011 He was with the RFIC/Mixed Signal group at Maxlinear from 2011-14 where he worked on silicon driven circuits and systems for broadband transceivers used in cable/satellite/infrastructure communication applications. From 2015, he has been an Assistant Professor of Electrical Engineering at Washington State University where he is supervising over Systems-on-Chip Lab. His current research interests include energy-efficient integrated circuits (IC) and systems for millimeter-wave communication and persistent sensing using information-aware signal processing for long-term monitoring.

MME Seminar Series Welcomes Dr. Praveen Thallapally, Pacific Northwest National Laboratory

Thursday in ETRL 101

Refreshments served in ETRL 119 at 10:30 am

Dr. Praveen K. Thallapally

 Pacific Northwest National Laboratory, Richland, WA

Ph.D in Chemistry and M.S. in Physical-Organic Chemistry, Ph.D. in Chemistry

 Advanced Nanostructured Materials for Selective Separation and Extraction

 

Abstract

In the materials science realm, porous materials, such as polymers, covalent organic frameworks (COFs), and metal organic frameworks (MOFs), are extremely valuable because of their stability and pore size. It is also easy to manipulate their chemistry. Typically, MOFs and COFs have the surface area of a football field, which enables them to capture and store large amounts of gas molecules and use as sensors. Similarly surface functionalization of MOF thin films on magnetic core particles were demonstrated for catalysis and separation applications. During my presentation I will touch up on two different applications (extraction of rare earth elements from geothermal brine solution and separation of noble gases from nuclear reprocessing plants) of MOFs that PNNL is working on.

 

Biography

My research is focused on the development of novel materials for energy applications, including catalysis, energy storage, carbon capture, and nuclear reprocessing. In the past 10 years I conducted both fundamental and applied research on a large number of novel crystalline organic and metal-organic frameworks (MOF) and membrane materials. The results of my research on synthesis, characterization and separation using porous organic and metal organic frameworks were published in more than 50 DOE technical reports and ~130 manuscripts in international peer-reviewed journals, as well as 6 reviews and 5 book chapters, The scientific impact of my research is evidenced by over 6800 citations and H-index of 47 (Google Scholar) attracted by these publications.

In addition to peer-review journals, the results of my work are disseminated through other professional publications. For example, research on MOFs membrane for CO2 separation was featured in 2013 Presidents Budget report; several other publications were featured on external websites, including Department of Energy – Office of Science website. I also contributed to a report to the Department of Energy on the first economic assessment of solid sorbents for CO2 capture from integrated gasification combined cycle (IGCC) power plants and first economic analysis report comparing room temperature separation of Xe and Kr from air to cryogenic separation process.

I supervise research by graduate and undergraduate students and mentor junior researchers. I am engaged with broad scientific community as a Topic Editor for Crystal Growth & Design, Advisory Board member for CrystEngComm and Journal of Coordination Chemistry, Guest Editor for Catalysis Today and community Board of Editor for Cryst. Grow & Des. Network. I also (co-)organize professional meetings at the national and international levels, including “Greenhouse Gas Emissions, Conversions and Utilization” (Denver, 2011), “CO2 Capture, Conversion and Utilization” (San Diego, 2012), “Metal Organic Frameworks for Energy and Fuels” (ACS, Philadelphia, 2012), and “Metal Organic Frameworks for Catalysis Applications” (ACS, Boston, 2015), as well as by facilitating scientific exchange as a discussion leader.

Finally, I work with sponsors and industrial partners in defining promising research directions going forward by participating in workshops related to NanoNuclear organized by Department of Energy – Office of Nuclear Energy and Brookhaven National Laboratory (2013) and serving as a reviewer for DOE, NSF and American petroleum research fund.

 

 

 

MME Seminar Series Welcomes Dr. Yogendra Joshi, Georgia Institute of Technology

Dr. Yogendra Joshi

G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology
Held in ETRL 101
Refreshments served in ETRL 119 at 10:30 am
Thermal Management and Design Approaches to
Enable Heterogeneous 3D Integration
Abstract

With the recent end of the International Technology Roadmap for Semiconductors, which has guided research on thermal packaging of microprocessors for nearly a quarter century, significantly different challenges are on the horizon.  Heterogeneous integration promises to bring in multiple functionalities in highly compact form factors via interposer based (2.5D) and three-dimensional (3D) stacked chip approaches.  Compared to planar integrated circuits (ICs), 3D stacked ICs as an emerging technology have significant advantages, including shorter interconnection length, smaller power consumption, and higher computation speed. However, chip stacking poses great challenges to thermal management.  Increased chip temperatures can degrade the reliability and performance, and increase the leakage power that constitutes a significant part of the total chip power. To mitigate these undesirable effects, advanced thermal management, such as microfluidic cooling can be employed. Very few experimental demonstrations of CMOS chips with integrated microfluidic cooling currently exist. In this presentation, inter-tier microfluidic cooling will be explored as a promising approach for future 3D stacked ICs due to its superior thermal performance and scalability. I will discuss ongoing research on microfluidic single phase and two phase cooling to address the high heat fluxes, and localized hot spots in these applications.  Examples of thermal/electrical co-design, which is essential for successful use of this technology will be presented for high performance and mobile applications. For the latter, thermal management and energy conservation must be simultaneously considered.  To fully utilize microfluidic cooling, reliable fluid delivery systems and good heat transfer fluids are required. It is concluded that extensive research on integration of inter-tier microfluidic cooling of 3D stacked ICs is still needed.

Biography

With the recent end of the International Technology Roadmap for Semiconductors, which has guided research on thermal packaging of microprocessors for nearly a quarter century, significantly different challenges are on the horizon.  Heterogeneous integration promises to bring in multiple functionalities in highly compact form factors via interposer based (2.5D) and three-dimensional (3D) stacked chip approaches.  Compared to planar integrated circuits (ICs), 3D stacked ICs as an emerging technology have significant advantages, including shorter interconnection length, smaller power consumption, and higher computation speed. However, chip stacking poses great challenges to thermal management.  Increased chip temperatures can degrade the reliability and performance, and increase the leakage power that constitutes a significant part of the total chip power. To mitigate these undesirable effects, advanced thermal management, such as microfluidic cooling can be employed. Very few experimental demonstrations of CMOS chips with integrated microfluidic cooling currently exist. In this presentation, inter-tier microfluidic cooling will be explored as a promising approach for future 3D stacked ICs due to its superior thermal performance and scalability. I will discuss ongoing research on microfluidic single phase and two phase cooling to address the high heat fluxes, and localized hot spots in these applications.  Examples of thermal/electrical co-design, which is essential for successful use of this technology will be presented for high performance and mobile applications. For the latter, thermal management and energy conservation must be simultaneously considered.  To fully utilize microfluidic cooling, reliable fluid delivery systems and good heat transfer fluids are required. It is concluded that extensive research on integration of inter-tier microfluidic cooling of 3D stacked ICs is still needed.

MME Seminar Series Welcomes: Dr. Tao Xing, University of Idaho

Held  in ETRL 101

Refreshments served in ETRL 119 at 10:30 am

Dr. Tao Xing, Ph.D., P.E.

Associate Professor, Department of Mechanical Engineering

University of Idaho, Moscow, Idaho

Solution Verification for Large Eddy Simulations
In Computational Fluid Dynamics

Abstract

With the dramatic growth of supercomputers, simulation based design, and ultimately virtual reality, have become increasingly important for the advancement of science and engineering.  Computational fluid dynamics (CFD) provides   computerized solutions for science and engineering problems using modeling, numerical methods, and high-performance computing. In CFD, the continuous partial differential equations are discretized into algebraic equations using numerical methods.  The algebraic equations are assembled and solved to get approximate solutions.  Thus, it is imperative to quantitatively estimate the numerical and modeling errors and associated uncertainties, which can only be achieved through rigorous verification and validation (V&V).  Additionally, guidelines for how to optimize a CFD simulation to obtain a minimum total simulation error are needed.  In this speech, definitions, general methodology and procedures of V&V will be covered. Based on statistical analysis, the “Factor of Safety” method shows advantages over various versions of the grid convergence index method, correction factor method, and least square method for Reynolds-averaged Navier-Stokes (RANS) V&V.  Nonetheless, these methods cannot be applied directly to large eddy simulations (LES) V&V.  Recently, a general framework for LES V&V was developed including a vast number methods based on two Hypotheses, ranging from a sophisticated seven-equation method to a simple single grid method. These methods were evaluated using implicitly filtered LES of periodic channel flows at friction Reynolds number of 395 on eight systematically refined grids. The seven-equation method shows that the coupling error based on Hypothesis I is much smaller as compared to the numerical and modeling errors and therefore can be neglected. The five-equation method based on Hypothesis II is recommended, which shows a monotonic convergence behavior of the predicted numerical benchmark (SC), and provides realistic error estimates without the need of fixing the orders of accuracy for either numerical or modeling errors. Based on the results from seven-equation and five-equation methods, less expensive three and four-equation methods for practical LES applications were derived. It was found that the new three-equation method is robust as it can be applied to any convergence types and reasonably predicts the error trends. It was also observed that the numerical and modeling errors usually have opposite signs in LES, which suggests error cancellation play an essential role in LES. When RANS verification method is applied, it shows significant error in the prediction of SC on coarse meshes. However, it predicts reasonable SC when the grids resolve at least 80% of the total turbulent kinetic energy.

Biography

Dr. Tao Xing earned his Ph.D. in Mechanical Engineering from Purdue University in 2002. He worked as a Postdoctoral    Fellow and Assistant Research Scientist at the Iowa Institute of Hydraulics Research from 2002 to 2008. He was an Assistant Professor from 2009 to 2016. Dr. Xing is currently an Associate Professor at University of Idaho. His research interests focus on both fundamental and applied CFD in multi-disciplines. Fundamental CFD research includes estimation of errors and uncertainties using quantitate solution verification and validation (V&V) method for turbulent flow simulations and entropy generation for bypass transitional boundary layers. For V&V, the “factor of safety method” he developed was evaluated as the most accurate and concise uncertainty estimates for monotonically converged numerical solutions.  He was invited to give 12 lectures including the keynote lecture on verification and validation in the 13th National Congress on Hydrodynamics in China in 2014. In 2015, he developed a general framework for V&V for large eddy simulations and very recently        five-equation and robust three-equation methods for LES V&V. Applied CFD research covers a broad range of disciplines including onshore and offshore wind turbine designs, vehicle aerodynamics, fluid-structure interaction for pulmonary ventilation, ship hydrodynamics, and desalination. Dr. Xing’s teaching interests focus on integration of simulation technology into engineering courses and laboratories, development of effective formative and summative evaluation   methods, and development of innovative teaching modules toward achieving ABET learning outcomes. His Google Scholar h-index and i10-index are 19 and 29, respectively. As a PI or Co-PI, he secured more than 1.8 million dollars funding since he joined the University of Idaho in 2011. He won the “Alumni Award” from the University of Idaho in 2013 and again in 2014. He won the “Outstanding Young Faculty Award” from College of Engineering in 2015. He is a licensed U.S. Professional  Engineer.

 

 

 

MME Seminar Series- Welcomes Dr. Charles Pezeshki, WSU Professor

Dr. Charles Pezeshki

Washington State University Professor, Director- Industrial Engagement

Seminar Starts at 11:00 am in ETRL 101

Refreshments served in ETRL 119 from 10:30 am to 11:00 am

Considering Research Ethics-

How do we develop our perception and truth in our results?
Abstract

Virtually all the graduate students and professors at WSU in engineering are involved in research efforts in one way or another. And while there is quite a bit of guidance on research process — we have internal reviews present in things like the IRB process, as well as conflicts of interest and their disclosure, for example — there’s very little on how we present new results, as well as the appropriate level to assert their truth

Biography

Dr. Pezeshki, or “Dr. Chuck” as he is known, will give a presentation on his work regarding the collective structure of knowledge that we create, as well as how human communities create knowledge, and the level of appropriate assertion of a given truth. Along the way, he’ll tour logical fallacies that the researcher should be aware of, as well giving some perspective on how we should pursue both reliability of results, as well as validity. He’ll end with two case studies, and their consequences, of what happens when researchers did not follow appropriate protocols, and will disclose the long-term consequences of those types of decisions, focusing on the use of sugar in the modern diet, and the Volkswagen emission scandal.