A5113965718- Thermal properties of materials
- Electronic Packaging and Soldering Technologies
- Heat Transfer and Optimization
- Thermography and Photoacoustic Techniques
- Heat Transfer and Boiling Studies
- Integrated Circuits and Semiconductor Failure Analysis
- Silicon Carbide Semiconductor Technologies
- 3D IC and TSV technologies
- Quantum and electron transport phenomena
- Silicon and Solar Cell Technologies
- Industrial Vision Systems and Defect Detection
- Advanced MEMS and NEMS Technologies
- Refrigeration and Air Conditioning Technologies
- Advanced Sensor Technologies Research
- Planetary Science and Exploration
- Heat Transfer Mechanisms
- Surface and Thin Film Phenomena
- Mechanical and Optical Resonators
- Graphene research and applications
- Astro and Planetary Science
- Topological Materials and Phenomena
- Force Microscopy Techniques and Applications
- Mechanical Behavior of Composites
- Material Properties and Processing
- Electrostatic Discharge in Electronics
Lamont-Doherty Earth Observatory
2025
Chemnitz University of Technology
2015-2024
Berliner Nanotest und Design
2016-2024
Stanford University
2023
TU Wien
2023
United States Department of Justice
2022
University of Quintana Roo
2022
University of Delaware
2019-2021
TU Dortmund University
2016-2020
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2018
Abstract In normal metals the magnetic moment of impurity-spins disappears below a characteristic Kondo temperature which marks formation cloud conduction-band electrons that screen local-moment. contrast, moments embedded in insulators remain unscreened at all temperatures. What then is fate magnetic-moments intermediate, pseudogap systems, such as graphene? Theory predicts coupling to will drive quantum phase transition between local-moment and Kondo-screened phase. However, attempts...
Abstract The vision of a deep learning-empowered non-destructive evaluation technique aligns perfectly with the goal zero-defect manufacturing, enabling manufacturers to detect and repair defects actively. However, dearth data in manufacturing is one biggest obstacles realizing an intelligent defect detection system. This work presents framework for bridging gap using potential synthetic datasets generated finite element method-based digital twin. under consideration pulse infrared...
Additiv gefertigte Aluminium-Matrix-Composite (AMC)-Materialien bieten durch ihr geringes Gewicht und ihre hohe Festigkeit signifikante Vorteile, führen aber während des Schweißvorgangs zu Porenbildung die beeinflussen. Im Rahmen der Förderbekanntmachung „WIR! – Wandel Innovation in Region“ Bundesministeriums für Bildung Forschung (BMBF) wird im Teilvorhaben „Inline-Prozesskettenentwicklung zum Reparieren von AMC-Werkstoffen sowie Porendetektion mittels aktiver IR-Thermographie zur...
The paper establishes foundational work for lock-in thermography as an in-line quality inspection tool during the production of power electronic devices. It focuses thereby on fast, reliable, and unequivocal detection defects, which reveal themselves through a characteristic transient thermal signature analysis phase amplitude images. experimental finite element analyses were performed at several excitation frequencies different numbers cycles excitation. A model was used to make...
Carbon point defects in graphene induce local magnetic moments the unbound \ensuremath{\sigma} orbital as well a ferromagnetically coupled bound state $\ensuremath{\pi}$ conduction band. The curvature of sheet determines hybridization strength to originally orthogonal Here, authors investigate two-orbital model, comprising two localized orbitals function gate-controlled chemical potential. They identify three different low-temperature regimes. corresponding distinct spectral functions agree...
Commentary On: Oswald, W. W., Foster, D. R., Shuman, B. N., Chilton, E. S., Doucette, L., Duranleau, L. Conservation implications of limited Native American impacts in pre-contact New England. Nature Sustainability https://doi.org/10.1038/s41893-019-0466-0
Although InP and GaAs have very similar band structure their magnetic properties appear to drastically differ. Critical temperatures in (In,Mn)P are much smaller than those of (Ga,Mn)As scale linearly with Mn concentration. This is contrast the square-root behavior found (Ga,Mn)As. Moreover magnetization curve exhibits an unconventional shape contrasting conventional one well-annealed By combining several theoretical approaches, nature ferromagnetism Mn-doped investigated. It appears that...
The steady state method is a commonly used and in principle simple way to measure thermal resistance conductivity of interface materials (TIMs). A heat flow through the TIM has be generated temperature gradient across measured. This also defined by ASTM standard D5470 [4]. To generate must positioned between hot cold plate. However, for new generation highly conductive thin TIMs resolution common technique often reaches its limit. increase equipment beyond state-of-the- art test systems...
The steady state method is a commonly used and in principle simple way to measure thermal resistance conductivity of interface materials (TIMs). sample must be positioned between hot cold plate with constant temperatures, whereby heat flow through the temperature gradient across are generated. To determine have measured. This also defined by ASTM standard D5470 [4]. However, for new generation highly conductive thin TIMs, die attach substrate resolution common technique often reaches its...
We study the conductance of a time-reversal-symmetric helical electronic edge coupled antiferromagnetically to magnetic impurity, employing analytical and numerical approaches. The impurity can reduce perfect ${G}_{0}$ noninteracting by generating backscattered current. steady-state current tends vanish below Kondo temperature ${T}_{K}$ for setups. show that central role in maintaining is played global $U(1)$ symmetry. This symmetry be broken an anisotropic exchange coupling modes local...
Flow boiling heat transfer to water of different cooler surface topologies is experimentally investigated. To have the possibility for investigations new electronic packages that supports cooling solutions by two-phase flow boiling, a multipurpose closed test stand rapid experimental characterization and parameter variation designed. The designed vehicle holds interchangeable, plug-in heating module offers investigate structures topologies/chemistry improve formation release small bubbles....
High-Performance Computing (HPC) is already becoming an essential part of many engineering fields, and automotive sector no exception. With the autonomous driving rapidly new technological forefront in ecosystem, peaks computing power automobiles will be seen, relying only on material developments to push this front further might prove vain. It therefore come up with solutions address challenges rising, such as increasing densities thermo-mechanical loads at a system level. To that end, we...
For the calculation of correct structure function, getting time constant spectrum is an important prerequisite. The time-constant result deconvolution derivative unit step response and weight function. However, ill-posed problem which needs utmost care. literature on function proposes two prominent solutions for step, namely Inverse Filtering Bayesian deconvolution. This research work implements both methods in algorithm compares obtained with analytical solution. On one hand, inverse...
One of the biggest hurdles in developing an innovative, intelligent failure analysis system that caters to needs manufacturing industry, is lack data train a deep learning driven system. The Finite Element Method (FEM) has potential bridge this gap by simulations encapsulate underlying physical phenomena form complex differential equations and solve them numerically. This work presents detailed study comparing results obtained for pulse thermography experiments FEM. Samples with artificially...
A composite material is a combination of two or more materials with very different mechanical, thermal and electrical properties. The various forms materials, due to their high properties, are widely used as structural in the aviation, space, marine, automobile, sports industries. However, some defects like voids, delamination, inhomogeneous fiber distribution that form during fabricating processes composites can seriously affect mechanical properties material. In this study, several imaging...
In this study we present the capabilities of an infrared failure analysis system to (automatically) detect defects in various samples from different fields application electronic industries. For purpose, developed a production line simulator with sample transfer via conveyor belt and integrated pulsed thermography system. With device it can be shown that such reach similar accuracy as conventionally used scanning acoustic microscopy detecting delamination voids sinter layers, molding...
This paper deals with the development of a new test stand for thermal diffusivity measurement based on Ångström's method (called TIMAwave™). The concept has been proved by FE simulation and experiments standard samples. realized integrated into hardware already existing LaTIMA™, which was developed conductivity highly conductive materials. combination these two stands in one device is great advantage, since sample can be measured at specimen device. results allow calculation specific heat...
In this paper, building blocks of a MEMS tensile testing platform are presented. The include thermo-mechanical actuator, driven by an aluminum thin-film heater on thermal oxide for electrical insulation, capacitative displacement sensor and piezoresistive force sensor, capable measuring forces nano-newton scale. It is shown, that the presented fulfill requirements use in loading stage material characterization one dimensional samples micro- nanoscopic scale under different environmental...
Transient thermal measurement is one of the most efficient ways to measure resistance electronic packages and perform a thorough structural analysis failure detection procedure. It well-accepted by industry determine junction-to-case (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">thJC</sub> ) as an indicator for performance device. In this paper, we will discuss development accurate, versatile compact transient system in compliance with...
Three different methods of failure analysis on die-attaches are presented and compared in the present work. For this purpose, specially designed samples with thermal test chips top have been used for a modulated excitation to investigate underlying die-attach layer by lock-in thermography [1]. The thermoreflectance infrared non-destructive which still must prove their abilities reliability find way into working production lines. results both verified common widely scanning acoustic...
This study shows a technique to avoid the necessary spray-coating of devices under test with low- emissivity surfaces in failure analyses by pulsed IR thermography. Such samples can be sintered or soldered electronic components. The mentioned is based on vacuum foil lamination process, which does not contaminate and saves time sample preparations. For this purpose, suitable optimal must found, was goal study. enables inline inspections industrial production lines non-destructive thermography...