Ag@Sn Core-Shell Powder Preform with a High Re-Melting Temperature for High-Temperature Power Devices Packaging

2017 ◽  
Vol 20 (1) ◽  
pp. 1700524 ◽  
Author(s):  
Fuwen Yu ◽  
Bin Wang ◽  
Qiang Guo ◽  
Xin Ma ◽  
Mingyu Li ◽  
...  
Keyword(s):  
High Temperature ◽  
Melting Temperature ◽  
Core Shell ◽  
Power Devices ◽  
Powder Preform ◽  
Shell Powder

Fabrication of Cu@Sn Core-Shell Structured Particles and the Application in High Remelting Temperature Bonding

2016 ◽  
Vol 878 ◽  
pp. 3-7 ◽  
Author(s):  
Tian Qi Hu ◽  
Hong Tao Chen ◽  
Ming Yu Li
Keyword(s):  
Electrical Conductivity ◽  
High Temperature ◽  
Thermal Shock ◽  
Harsh Environments ◽  
Core Shell ◽  
Power Devices ◽  
Reflow Soldering ◽  
Bonding Material ◽  
Die Attach ◽  
Reflow Temperature

A novel solder bonding material for high-temperature applications based on Cu@Sn core-shell structured particles was developed, and the fabricated Cu@Sn particles were compressed into preforms for die attachment. The reflow temperature for this bonding material could reached as low as 260°C due to the low melting temperature of the outer Sn layer. However, after reflow soldering, the resulting interconnections can withstand a high temperature of at least 415°C, outer Sn layer completely transformed into Cu-Sn intermetallic compounds (IMCs) with high remelting temperatures. The formed bondlines exhibit good electrical conductivity due to the low porosity and the embedded Cu particles in the interconnections. Furthermore, the interconnections also exhibit excellent reliability under thermal shock cycling from-55°C to 200°C. This die attach material is suitable for power devices operating under high temperatures or other harsh environments.

High-Temperature Synthesis of CdSe-Based Core/Shell, Core/Shell/Shell, and Core/Graded-Shell Nanoplatelets for Stable and Efficient Narrowband Emitters

2019 ◽  
Author(s):  
Aurelio A. Rossinelli ◽  
Henar Rojo ◽  
Aniket S. Mule ◽  
Marianne Aellen ◽  
Ario Cocina ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Temperature ◽  
Equilibrium Shape ◽  
Size Variation ◽  
Crystal Defects ◽  
Atomic Scale ◽  
Quantum Yields ◽  
Core Shell ◽  
Compositional Gradient ◽  
High Quality

<div>Colloidal semiconductor nanoplatelets exhibit exceptionally narrow photoluminescence spectra. This occurs because samples can be synthesized in which all nanoplatelets share the same atomic-scale thickness. As this dimension sets the emission wavelength, inhomogeneous linewidth broadening due to size variation, which is always present in samples of quasi-spherical nanocrystals (quantum dots), is essentially eliminated. Nanoplatelets thus offer improved, spectrally pure emitters for various applications. Unfortunately, due to their non-equilibrium shape, nanoplatelets also suffer from low photo-, chemical, and thermal stability, which limits their use. Moreover, their poor stability hampers the development of efficient synthesis protocols for adding high-quality protective inorganic shells, which are well known to improve the performance of quantum dots. <br></div><div>Herein, we report a general synthesis approach to highly emissive and stable core/shell nanoplatelets with various shell compositions, including CdSe/ZnS, CdSe/CdS/ZnS, CdSe/Cd<sub>x</sub>Zn<sub>1–x</sub>S, and CdSe/ZnSe. Motivated by previous work on quantum dots, we find that slow, high-temperature growth of shells containing a compositional gradient reduces strain-induced crystal defects and minimizes the emission linewidth while maintaining good surface passivation and nanocrystal uniformity. Indeed, our best core/shell nanoplatelets (CdSe/Cd<sub>x</sub>Zn<sub>1–x</sub>S) show photoluminescence quantum yields of 90% with linewidths as low as 56 meV (19.5 nm at 655 nm). To confirm the high quality of our different core/shell nanoplatelets for a specific application, we demonstrate their use as gain media in low-threshold ring lasers. More generally, the ability of our synthesis protocol to engineer high-quality shells can help further improve nanoplatelets for optoelectronic devices.</div>

First Demonstration of High Temperature SiC CMOS Gate Driver in Bridge Leg for Hybrid Power Module Application

2018 ◽  
Vol 924 ◽  
pp. 854-857
Author(s):  
Ming Hung Weng ◽  
Muhammad I. Idris ◽  
S. Wright ◽  
David T. Clark ◽  
R.A.R. Young ◽  
...  
Keyword(s):  
High Temperature ◽  
Integrated Circuits ◽  
Initial Increase ◽  
Reliability Test ◽  
Power Devices ◽  
Power Module ◽  
Hybrid Power ◽  
Gate Driver ◽  
Passive Circuit

A high-temperature silicon carbide power module using CMOS gate drive technology and discrete power devices is presented. The power module was aged at 200V and 300 °C for 3,000 hours in a long-term reliability test. After the initial increase, the variation in the rise time of the module is 27% (49.63ns@1,000h compared to 63.1ns@3,000h), whilst the fall time increases by 54.3% (62.92ns@1,000h compared to 97.1ns@3,000h). The unique assembly enables the integrated circuits of CMOS logic with passive circuit elements capable of operation at temperatures of 300°C and beyond.

LTCC Embedding of SiC Power Devices for High Temperature Applications over 400 °C

2020 ◽  
Author(s):  
Benjamin Bayer ◽  
Mario Groccia ◽  
Hoang Linh Bach ◽  
Christoph Friedrich Bayer ◽  
Andreas Schletz ◽  
...  
Keyword(s):  
High Temperature ◽  
Power Devices ◽  
Temperature Applications

Improvement of Minority Carrier Lifetime in Thick 4H-SiC Epi-layers by Multiple Thermal Oxidations and Anneals

2013 ◽  
Vol 1538 ◽  
pp. 329-333 ◽  
Author(s):  
Lin Cheng ◽  
Michael J. O’Loughlin ◽  
Alexander V. Suvorov ◽  
Edward R. Van Brunt ◽  
Albert A. Burk ◽  
...  
Keyword(s):  
High Temperature ◽  
Carrier Lifetime ◽  
Minority Carrier ◽  
Minority Carrier Lifetime ◽  
Power Devices ◽  
Oxidation Treatment ◽  
Temperature Oxidation ◽  
Oxidation Step ◽  
High Temperature Anneal ◽  
Lifetime Enhancement

ABSTRACTThis paper details the development of a technique to improve the minority carrier lifetime of 4H-SiC thick (≥ 100 μm) n-type epitaxial layers through multiple thermal oxidations. A steady improvement in lifetime is seen with each oxidation step, improving from a starting ambipolar carrier lifetime of 1.09 µs to 11.2 µs after 4 oxidation steps and a high-temperature anneal. This multiple-oxidation lifetime enhancement technique is compared to a single high-temperature oxidation step, and a carbon implantation followed by a high-temperature anneal, which are traditional ways to achieve high ambipolar lifetime in 4H-SiC n-type epilayers. The multiple oxidation treatment resulted in a high minimum carrier lifetime of 6 µs, compared to < 2 µs for other treatments. The implications of lifetime enhancement to high-voltage/high-current 4H-SiC power devices are also discussed.

scholarly journals Achieving high strength and ductility in ODS-W alloy by employing oxide@W core-shell nanopowder as precursor

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhi Dong ◽  
Zongqing Ma ◽  
Liming Yu ◽  
Yongchang Liu
Keyword(s):  
High Temperature ◽  
Metal Matrix ◽  
High Performance ◽  
High Energy ◽  
Core Shell ◽  
Microstructural Stability ◽  
Oxide Particles ◽  
Ods Alloy ◽  
Prepared Alloy ◽  
Strength And Ductility

AbstractWith excellent creep resistance, good high-temperature microstructural stability and good irradiation resistance, oxide dispersion strengthened (ODS) alloys are a class of important alloys that are promising for high-temperature applications. However, plagued by a nerve-wracking fact that the oxide particles tend to aggregate at grain boundary of metal matrix, their improvement effect on the mechanical properties of metal matrix tends to be limited. In this work, we employ a unique in-house synthesized oxide@W core-shell nanopowder as precursor to prepare W-based ODS alloy. After low-temperature sintering and high-energy-rate forging, high-density oxide nanoparticles are dispersed homogeneously within W grains in the prepared alloy, accompanying with the intergranular oxide particles completely disappearing. As a result, our prepared alloy achieves a great enhancement of strength and ductility at room temperature. Our strategy using core-shell powder as precursor to prepare high-performance ODS alloy has potential to be applied to other dispersion-strengthened alloy systems.

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