A5100739608- Electronic Packaging and Soldering Technologies
- 3D IC and TSV technologies
- Nanomaterials and Printing Technologies
- Advanced MEMS and NEMS Technologies
- Semiconductor materials and devices
- Advanced Photonic Communication Systems
- Optical Network Technologies
- Nanowire Synthesis and Applications
- Silicon Nanostructures and Photoluminescence
- Aluminum Alloys Composites Properties
- Advanced Surface Polishing Techniques
- Photonic and Optical Devices
- Microfluidic and Capillary Electrophoresis Applications
- Advanced Sensor and Energy Harvesting Materials
- Advancements in Semiconductor Devices and Circuit Design
- Advanced Optical Network Technologies
- Injection Molding Process and Properties
- Copper Interconnects and Reliability
- Mechanical and Optical Resonators
- Advanced Welding Techniques Analysis
- Analytical Chemistry and Sensors
- nanoparticles nucleation surface interactions
- Semiconductor Lasers and Optical Devices
- Fuel Cells and Related Materials
- Intermetallics and Advanced Alloy Properties
Seoul National University of Science and Technology
2016-2025
Seoul National University
2009-2024
Gwangju Institute of Science and Technology
2003-2024
Gyeongsang National University
2012-2024
Yonsei University
2012-2024
Hanyang University
2006-2024
Korea Institute of Industrial Technology
2007-2023
Korea Institute of Civil Engineering and Building Technology
2013-2023
Sungkyunkwan University
2022
Technical University of Denmark
2019-2021
In this study, we report the successful demonstration of an intermediate-frequency-over-fiber (IFoF)-based radio access network (RAN) for 28 GHz millimeter-wave (mmWave)-based 5G mobile communication. order to increase coverage mmWave-based networks, propose a distributed antenna system (DAS) that uses IFoF technology. An IFoF-based DAS with 2 × multiple-input multiple-output (MIMO) configuration was deployed in PyeongChang area provide trial during Winter Olympics. services such as...
Operating temperature of a wide-bandgap semiconductor-based power device can reach 300 °C, which requires next-generation die-attach sinter material. Ag-coated Cu (Cu@Ag) particles have been considered as low-cost filler material in pastes for bonding, replacing pure Ag particles. However, there are two main problems: out-diffusion core and dewetting. Although the shell is sufficiently thick, dewetting induces accelerated resultant oxidation through formation thin coating parts. Accordingly,...
Recently, small-scale and highly-distributed photovoltaic power sources have been researched for the high generation efficiency even under severe partial shading conditions. However, conditioning systems needs step-up voltage gain due to low output of generating sources. This paper presents a newly-suggested topology employing Series-connected Forward-FlyBack (SFFB) converter, which has series-connected boosting voltage-transfer gain. SFFB is hybrid type forward flyback sharing transformer...
This study examines the oxidation behavior of Ag-coated Cu (Cu@Ag) nanoparticles (NPs) less than 20 nm in size synthesized using a solvothermal method and an immersion process with varying Ag shell quality. The anti-oxidation property Cu@Ag NPs was strongly dependant on
The application of wide-bandgap semiconductors in next-generation power modules requires cost-effective Cu particles and a reduced bonding time the die attachment process to enable efficient industrial-scale manufacturing. Therefore, this study aimed analyze effect particle size variation on pressure-assisted sinter-bondability bond line shear strength. were synthesized through simple wet-chemical process, which pH was employed obtain submicrometer-sized with average diameters 500, 300, 150...
This paper is focused on the analysis of shielding properties reinforced concrete under impinging high-altitude electromagnetic pulse. The provides frequency-dependent effectiveness mainly due to embedded metallic grid rebars. For characterization concrete, three different configurations, i.e., rebar, and combined are analyzed in detail. In addition, quantitatively by its frequency dependence, moisture content, material mixture ratio. According obtained results, as rebar spacing decreases...
To promptly form a bondline with high thermal stability and conductivity using small amount of expensive Ag, dies were attached to Ag finishes by pressure-assisted sinter bonding at 300 °C micrometer-sized Ag-coated Cu ([email protected]) flakes. Small [email protected] particles 350 nm size also added the paste increase sinterability increasing contact points, which resulted in bimodal paste. The dewetting shells induced initial sintering, rearrangement as well bending flakes under pressure...
Pressure-assisted sinter bonding between an Ag-finished die and substrate was performed in air using Ag-coated Cu (Cu@Ag) particulate preform to rapidly achieve a bondline with high-temperature sustainability, low-defect structure, high thermal conductivity. The prepared as binder-free material by pelletizing 351 nm Cu@Ag particles 20 wt.% Ag shells. At 350 °C at pressures of 5 MPa 10 MPa, the exhibited shear strength values approaching 24 respectively, just after 30 s pressure increase...
Despite evidence linking a safety culture with patient safety, the processes by which aspect of influences are not yet well understood. Thus, this study aimed to test theoretical model relationships between three enabling factors (supervisor/clinical leader support for hospital management and psychological safety), four enacting (handoffs information exchange, teamwork, error reporting intention, withholding voice) nurse assessments safety.A cross-sectional, descriptive correlational design...
This paper presents a micromachined in-plane tunable optical filter using the thermo-optic effect of crystalline silicon. The device was fabricated by silicon deep reactive ion etching process with silicon-on-insulator wafer and thermal oxide removal to improve sidewall smoothness. Optical fibers could be horizontally aligned on TOF exploiting structures, which enable TOFs easily connect other components. Tunability experimentally achieved through modulation path length heating etalon. As...
Nickel silicide (NiSi) was formed by annealing a uniform low-resistivity nickel (Ni) film deposited atomic layer deposition (ALD). A Ni as-deposited at 220 °C exhibited the lowest sheet resistance of 18 Ω/sq. comparable to that obtained physical vapor deposition, even though it contained significant amount carbon from metalorganic precursor. It is believed uniformly distributed in partly forming weak Ni3C phase which eliminates other crystalline defects and hence lowers film. However, not...