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Institution

Sandia National Laboratories

FacilityLivermore, California, United States
About: Sandia National Laboratories is a facility organization based out in Livermore, California, United States. It is known for research contribution in the topics: Laser & Combustion. The organization has 21501 authors who have published 46724 publications receiving 1484388 citations. The organization is also known as: SNL & Sandia National Labs.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the growth and mechanical behavior of interfacial intermetallics between copper and six solder alloys commonly used in electronics assembly were examined. And the fracture behavior of the joints in tension was dependent upon the strength of the solder alloy.
Abstract: The presence of an intermetallic is often an indication of good wetting in a solder joint. However, excessive intermetallic growth and the brittleness of the intermetallic layer may be detrimental to joint reliability. This study examined the growth and mechanical behavior of interfacial intermetallics between copper and six solder alloys commonly used in electronics assembly. The solder alloys tested were 60Sn-40Pb, 63Sn-37Pb, 95Sn-5Sb, 96.5Sn-3.5Ag, 50Pb-50In, 50Sn-50In, and 40In-40Sn-20Pb. The 50Sn-50In and 40In-40Sn-20Pb exhibited faster solid state growth of the intermetallic layer at 100 °C as compared to the near-eutectic Sn-Pb control solder. The 50In-50Pb had a slower growth rate, relative to 63Sn-37Pb, at the aging temperature of 170 °C due to slower reaction rate kinetics of indium with copper. The 96.5Sn-3.5Ag and 95Sn-5Sb had similar intermetallic growth rates at 170 °C and 205 °C, and the aging was comparable to that of the 63Sn-37Pb alloy. The 95Sn-5Sb solder/copper intermetallic had a faster growth rate of the Cu3Sn layer than was observed in the Sn-Ag or Sn-Pb alloys. Modified fracture toughness and low load indentation tests were used to characterize the mechanical behavior of the intermetallics. The intermetallics were harder than both the base metal and the solder alloy. The fracture behavior of the joints in tension was dependent upon the strength of the solder alloy. Solders with low strengths failed in the solder by plastic deformation. The failure of solders with higher strengths was dependent upon intermetallic thickness. When the intermetallic was thin, fracture occurred in the solder or at the solder/ intermetallic interface. As the interfacial intermetallic thickened, the fracture path moved into the intermetallic layer.

261 citations

Journal ArticleDOI
TL;DR: In this paper, the properties of mixed aluminophosphate glass were investigated for aluminum electrical connectors and showed that tetrahedral borons are preferred in xB 2 O 3 (1-x)(PO 3 ) 2 and in yB 2 o 3 ( 1 - y)Zn 2 P 2 O 7 glasses for x < 0.4 and y < 0.2.
Abstract: Requirements for enhanced component performance and reliability have led to the development of novel glass compositions for a variety of hermetic sealing applications. The development of technologically useful glass compositions was based on an understanding of the relationships between the molecular-level glass structure and important physical properties. The properties of the alkaline earth aluminoborate glasses for lithium batteries are sensitive to changes in B- and Al-coordination number, characterized by solid state nuclear magnetic resonance (NMR) spectroscopy. In general, the most useful compositions have structures that are dominated by tetrahedral Band Al-sites. Mixed alkali aluminophosphate glasses were developed for aluminum electrical connectors. The properties of sodium aluminophosphate glasses depend on the O/P ratio and significant property changes (e.g. maxima in T g and refractive index) occur when O/P exceeds the pyrophosphate limit at 3.5. Associated with these property changes is a decrease in the average Al-coordination number, from six to four, at O/P > 3.5. Raman spectroscopy provides additional information about the aluminophosphate network. Finally, zinc borophosphate glasses are developed for seals in flat panel displays. Boron-11 NMR shows that tetrahedral borons are preferred in xB 2 O 3 (1-x)(PO 3 ) 2 and in yB 2 O 3 (1 - y)Zn 2 P 2 O 7 glasses for x < 0.4 and y < 0.2. Raman spectroscopy reveals the concomitant evolution from a phosphate to a borophosphate network with increasing x and y.

261 citations

Journal ArticleDOI
TL;DR: Poor performance of regression-based sensitivity analysis procedures for some analysis outcomes results more from the inappropriateness of the procedure for the nonlinear relationships between model input and model results than from an inadequate sample size.

261 citations

Patent
25 Oct 2002
TL;DR: In this paper, a modular apparatus for and method of alternating current photovoltaic power generation comprising via a PV module, generating power in the form of direct current; and converting direct current to alternating current and exporting power via one or more power conversion and transfer units attached to the module, each unit comprising a unitary housing extending a length or width of the module.
Abstract: A modular apparatus for and method of alternating current photovoltaic power generation comprising via a photovoltaic module, generating power in the form of direct current; and converting direct current to alternating current and exporting power via one or more power conversion and transfer units attached to the module, each unit comprising a unitary housing extending a length or width of the module, which housing comprises: contact means for receiving direct current from the module; one or more direct current-to-alternating current inverters; an alternating current bus; and contact means for receiving alternating current from the one or more inverters.

261 citations

Journal ArticleDOI
TL;DR: The ability to recover the velocity profile from a time sequence of these scalar images by direct inversion of the conserved scalar advection-convection equation is demonstrated.
Abstract: A new tool for imaging both scalar transport and velocity fields in liquid flows through microscale structures is described. The technique employs an ultraviolet laser pulse to write a pattern into the flow by uncaging a fluorescent dye. This is followed, at selected time delays, by flood illumination with a pulse of visible light which excites the uncaged dye. The resulting fluorescence image is collected onto a sensitive CCD camera. The instrument is designed as an oil immersion microscope to minimize beam steering effects. The caged fluorescent dye is seeded in trace quantities throughout the active fluid, thus images with high contrast and minimal distortion due to any molecular diffusion history can be obtained at any point within the microchannel by selectively activating the dye in the immediate region of interest. We report images of pressure- and electrokinetically driven steady flow within round cross section capillaries having micrometer scale inner diameters. We also demonstrate the ability to recover the velocity profile from a time sequence of these scalar images by direct inversion of the conserved scalar advection-convection equation.

261 citations


Authors

Showing all 21652 results

NameH-indexPapersCitations
Lily Yeh Jan16246773655
Jongmin Lee1502257134772
Jun Liu13861677099
Gerbrand Ceder13768276398
Kevin M. Smith114171178470
Henry F. Schaefer111161168695
Thomas Bein10967742800
David Chandler10742452396
Stephen J. Pearton104191358669
Harold G. Craighead10156940357
Edward Ott10166944649
S. Das Sarma10095158803
Richard M. Crooks9741931105
David W. Murray9769943372
Alán Aspuru-Guzik9762844939
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202340
2022245
20211,510
20201,580
20191,535
20181,514