A high-temperature octopole ion guide for measuring absolute cross sections of ion–metal atom reactions

1997 ◽  
Vol 68 (1) ◽  
pp. 64-69 ◽  
Author(s):  
Dale J. Levandier ◽  
Rainer A. Dressler ◽  
Edmond Murad
Keyword(s):  
High Temperature ◽  
Metal Atom ◽  
Cross Sections ◽  
Ion Guide ◽  
Metal Atom Reactions

scholarly journals High temperature infrared absorption cross sections of methane near 3.4 µm in Ar and CO2 mixtures

2018 ◽  
Vol 206 ◽  
pp. 36-45 ◽  
Author(s):  
Batikan Koroglu ◽  
Sneha Neupane ◽  
Owen Pryor ◽  
Robert E. Peale ◽  
Subith S. Vasu
Keyword(s):  
High Temperature ◽  
Cross Sections ◽  
Infrared Absorption ◽  
Absorption Cross

Metal atom reactions with fluorocarbons. 9. Preparation and spectral analyses of (perfluoroalkyl)- and (perfluoroaryl)palladium halides

1980 ◽  
Vol 19 (12) ◽  
pp. 3719-3724 ◽  
Author(s):  
Kenneth J. Klabunde ◽  
Bruce B. Anderson ◽  
Kent Neuenschwander
Keyword(s):  
Metal Atom ◽  
Spectral Analyses ◽  
Metal Atom Reactions

Mobile Packaging and Interconnect Trends

2014 ◽  
Vol 2014 (DPC) ◽  
pp. 1-21
Author(s):  
Brandon Prior
Keyword(s):  
Shear Strength ◽  
High Temperature ◽  
Thick Film ◽  
Cross Sections ◽  
Shear Test ◽  
Short Review ◽  
Test Machine ◽  
Die Attach ◽  
Shear Failures ◽  
Film Substrate

This paper will focus on emerging and fast growth package solutions to meet mobile products' density and cost requirements. A short review of where package miniaturization and modularization has taken us so far, and where it will lead in the next 5 years. Teardowns of high density systems and packages will be used to illustrate key points. Low temperature Ag sintering technology provides a lead-free die attachment compatible with high temperature (300°C) applications. Previous work with Ag sintering has required some pressure during the sintering process or been limited to small area die. In this paper, a pressureless sintering of micro-scale silver paste procedure is presented for large (8mm x 8mm) area die. Experimental combinations included: Ag metallized Si die, Au metallized Si die, Ag thick film substrate metallization, Au thick film substrate metallization, PdAg thick film metallization and sintering temperature. For Au metallization (die and/or substrate), the initial shear strength results were good with 8mm x 8mm die sintered at lower temperatures (200°C). The shear strength was out range of our shear test machine (100 kg), corresponding to >15.3 MPa. However, after aging for 24 hours at 300°C, the shear strength dropped significantly to 40.38 Kg (6.183 MPa). An SEM was used to characterize cross sections of as-built and aged sample. The decrease in die shear strength with high temperature sintering (250°C and 300°C) or high temperature aging is attributed to surface diffusion of Ag along the Au surface resulting in a dense Ag layer adjacent to the Au surface and a depletion layer within the die attach on the opposite side of the the dense Ag layer. Shear failures occurred through the depleted region. For Ag metallization, no decrease in shear strength was observed with 300°C aging. Shear strength of 8x8cm2 dies was out range of our shear test machine (>100 kg, >15.3 MPa) as-built. The shear strength remained out of range (>15.3MPa) after more than 2000 hours of 300C aging.

Au-Sn SLID bonding for high temperature applications

2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000058-000067 ◽  
Author(s):  
Torleif André Tollefsen ◽  
Andreas Larsson ◽  
Knut Aasmundtveit
Keyword(s):  
High Temperature ◽  
Cross Sections ◽  
Cost Effective ◽  
Stress Tests ◽  
Packaging System ◽  
Bonding Properties ◽  
Bond Interface ◽  
Processing Techniques ◽  
Solid Liquid ◽  
Interconnect Technology

Au-Sn solid-liquid-interdiffusion (SLID) bonding is a novel and promising interconnect technology for high temperature (HT) applications. In combination with Silicon Carbide (SiC) devices, Au-Sn SLID has the potential of being a key technology for the next generation of innovative, cost effective and environmentally friendly drilling and well intervention systems for the oil industry. However, limited knowledge about Au-Sn SLID bonding for combined HT and high power applications is a major restriction to fully realize the high temperature potential of SiC devices. This paper presents a comprehensive study of fluxless Au-Sn SLID bonding. Two different processing techniques – electroplating of Au / Sn layers and sandwiching of eutectic Au-Sn preform between electroplated Au layers – have been studied in a simplified metallization system. The latter process was further investigated in two different Cu / Si3N4 / Cu / NiP / Au-Sn / Ni / Ni2Si / SiC systems (different Au-layer thickness). Die shear tests and cross-sections have been performed on “as bonded”, thermally cycled and thermally aged samples to characterize the bonding properties associated with the different processing techniques, metallization schemes and environmental stress tests. A uniform Au-rich bond interface is produced (the ζ phase with a melting point of 522 °C). The importance of excess Au on both substrate and chip side in the final bond is demonstrated. It is shown that Au-Sn SLID can absorb thermo-mechanical stresses induced by large CTE mismatches (up to 12 ppm/K) in a packaging system during HT thermal cycling. The bonding strength of Au-Sn SLID is shown to be superb, exceeding 78 MPa. Importantly, Au-Sn SLID is shown to be an excellent interconnect technology for HT packaging.

scholarly journals Premature destruction of two-span RC beams exposed to high temperature caused by a redistribution of shear forces

2016 ◽  
Vol 23 (4) ◽  
pp. 431-439 ◽  
Author(s):  
Robert KOWALSKI ◽  
Michał GŁOWACKI ◽  
Marian ABRAMOWICZ
Keyword(s):  
High Temperature ◽  
Cross Sections ◽  
Bending Moment ◽  
Middle Part ◽  
Transverse Reinforcement ◽  
Shear Load ◽  
Bending Moments ◽  
Rc Beams ◽  
Shear Forces ◽  
Load Bearing Capacity

When multi-span RC elements are exposed to fire one usually observes a yielding of span cross-sections while a safety reserve of support cross-sections is still significant. Due to this phenomenon a redistribution of bending moments occurs and the values of sagging moment in span cross-sections decrease while the values of hogging moment in support cross-sections increase. This paper shows the results of tests conducted on two-span RC beams in a situation when only one span has been exposed to high temperature from the bottom. The beams were 12×16 cm in their cross-section. The length of the span was 165 cm. The load has been applied by two forces put on each span. The beams were made of C25/30 concrete with siliceous aggregate. As a result of significant stiffness decrease of the heated span, redistribution of shear forces and bending moment occurs. Due to this redistribution the tested beams were prematurely damaged due to exhaust of the shear load bearing capacity in the middle part of the beam span where there was no transverse reinforcement.

New high temperature resistant heavy concretes for fast neutron and gamma radiation shielding

2019 ◽  
Vol 107 (4) ◽  
pp. 359-367 ◽  
Author(s):  
Bünyamin Aygün ◽  
Erdem Şakar ◽  
Turgay Korkut ◽  
Mohammed Ibrahim Sayyed ◽  
Abdülhalik Karabulut
Keyword(s):  
High Temperature ◽  
Cross Sections ◽  
Gamma Ray ◽  
Mean Free Path ◽  
Mass Attenuation Coefficient ◽  
Normal Weight ◽  
Radiation Shielding ◽  
Equivalent Dose Rate ◽  
Normal Weight Concrete ◽  
Geant4 Code

Abstract In the present work, we developed three new high temperature resistant heavy concretes as novel radiation shielding materials. For this purpose, chrome ore (FeCr2O4), hematite (Fe2O3), titanium oxide (TiO2), aluminum oxide (Al2O3), limonite [FeO (OH) nH2O], siderite (FeCO3), barite (BaSO4), nickel oxide (NiO) materials and alumina cement were used. Mass combination ratios of components and total macroscopic cross sections (scattering, absorption, capture, fission) of the samples were calculated by using GEANT4 code. The resistances of the prepared samples were evaluated in terms of compression strength after exposure at the 1000 °C temperature. Neutron equivalent dose rate measurements were carried out by using 4.5 MeV 241Am-Be neutron source and BF3 detector. All results were compared with normal weight concrete and paraffin. The results of neutron dose indicate that neutron absorption ability of the new heavy concretes is higher than normal weight concrete and paraffin. In addition to neutron measurements, different γ-ray shielding parameters such as mass attenuation coefficient (MAC), effective atom numbers (Zeff), half value layer (HVL) and mean free path (MFP) have been calculated using WinXCOM software in order to investigate the effectiveness of using the prepared concretes as a radiation shielding materials. Gamma-ray results were compared with concretes and Pb-based glass.

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