Materials

Differential Muon Tomography to Continuously Monitor Changes in the Composition of Subsurface Fluids

This innovation enables tracking of carbon storage or enhanced oil recovery in subsurface reservoir projects. Muon tomography has been used to seek hidden chambers in Egyptian pyramids and image subsurface features in volcanoes. It seemed likely that it could be used to image injected, supercritical carbon dioxide as it is emplaced in porous geological structures being used for carbon sequestration, and also to check on subsequent leakage. It should work equally well in any other application where there are two fluids of different densities, such as water and oil, or carbon dioxide and heavy oil in oil reservoirs.

Posted in: Materials, Briefs, TSP

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Conductive Carbon Nanotube Inks for Use with Desktop Inkjet Printing Technology

A mixture of carbon nanotubes and silver or gold nanoparticles could be applied by inkjet printing to flexible substrates. Inkjet printing is a common commercial process. In addition to the familiar use in printing documents from computers, it is also used in some industrial applications. For example, wire manufacturers are required by law to print the wire type, gauge, and safety information on the exterior of each foot of manufactured wire, and this is typically done with inkjet or laser printers.

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Enhanced Schapery Theory Software Development for Modeling Failure of Fiber-Reinforced Laminates

This tool captures the physics of the damage and failure mechanisms. Progressive damage and failure analysis (PDFA) tools are needed to predict the nonlinear response of advanced fiber-reinforced composite structures. Predictive tools should incorporate the underlying physics of the damage and failure mechanisms observed in the composite, and should utilize as few input parameters as possible.

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High-Performance, Low-Temperature-Operating, Long-Lifetime Aerospace Lubricants

The synthesis and characterization of six new ionic liquids, with fluoroether moeties on the imidazolium ring, each with vapor pressures shown to be

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Carbon Nanotube Microarrays Grown on Nanoflake Substrates

This process creates materials comprised predominantly of single-walled carbon nanotubes. This innovation consists of a new composition of matter where single-walled carbon nanotubes (SWNTs) are grown in aligned arrays from nanostructured flakes that are coated in Fe catalyst. This method of growth of aligned SWNTs, which can yield well over 400 percent SWNT mass per unit substrate mass, exceeds current yields for entangled SWNT growth. In addition, processing can be performed with minimal wet etching treatments, leaving aligned SWNTs with superior properties over those that exist in entangled mats.

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A Room Temperature, Low-Stress Bonding Process to Reduce the Impact of Use Stress on a Sputtering Target Assembly

As semiconductor processing has moved to 300mm wafers, the size of deposition targets, including tungsten (W), tantalum (Ta), and molybdenum (Mo), has grown, and process complexity has increased as well. This added size and complexity contributes to the stress on a target assembly during the physical vapor deposition (PVD) process, and the target assembly’s ability to withstand this stress has a large effect on the resulting deposition rates, yields, and film properties. One of the major sources of stress is the coefficient of thermal expansion (CTE) mismatch between metal targets in semiconductor processes, such as tungsten (CTE of 4.5*10-6/°C), tantalum (6.5*10-6/°C), and molybdenum (5.1*10-6/°C) compared with their backing plates, which are typically made of aluminum (23*10-6/°C), brass (21.2*10-6/°C), or copper-chrome (17.6*10- 6/°C). Standard soldering and solid state joining processes have difficulty controlling stress produced by the CTE-mismatch. We will demonstrate how the NanoBond® process can be used to control stresses during the bonding and deposition processes. Modeling will be conducted to compare standard bonding processes to the NanoBond process, accounting for CTE mismatches.

Posted in: Materials, White Papers

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Achieving High Reliability SAC Solder Joints via Min Doping

In this study, the reliability of low Ag SAC alloy doped with Mn (SACM) was evaluated under JEDEC drop, dynamic bending, thermal cycling, and cyclic bending test conditions and compared to eutectic SnPb, SAC105, and SAC305 alloys. SACM is a patent pending alloy consisting of 0.5-1% Ag, 0.5-1% Cu, <0.1% Mn. SACM alloy achieved a higher drop test and dynamic bending test reliability than SAC105 and SAC305, and exceeded SnPb for many test conditions. More significantly, SACM matched SAC305 in thermal cycling performance. In other words, the low cost SACM achieved a better drop test performance than the low Ag SAC alloys, plus the desired thermal cycling reliability of high Ag SAC alloys. The mechanism for high drop shock performance and high thermal cycling reliability can be attributed to a stabilized microstructure, with uniform distribution of fine IMC particles, presumably through the inclusion of Mn in the IMC. The cyclic bending results showed SAC305 to be the best and all lead-free alloys were equal or superior to SnPb. The reliability test results also showed that NiAu is a preferred surface finish for BGA packages over OSP.

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