Comment on “Effects of focused ion beam milling on the nanomechanical behavior of a molybdenum-alloy single crystal” Appl. Phys. Lett. 91, 111915 (2007)

While this article provides insight into differences in mechanics between Ga+-irradiated and “pure” surfaces of molybdenum, there are several statements that are either inaccurate or poorly stated. It is clear that when a surface is directly irradiated by orthogonal ion beam (0.07–0.21 mW), a focused ion beam (FIB) damage layer will likely form and affect the strength. However, this finding does not provide adequate foundation for raising the question of FIB-induced hardening in nanopillars, given the vast differences between these experiments and procedure used in pillar fabrication. These issues would cause considerable confusion and result in disservice to mechanical testing community if not clarified

Concert recording 2022-04-02b

[Track 1]. Act 1

Concert recording 2022-04-02b

[Track 1]. Act 1

Optimization of Indium Bump Morphology for Improved Flip Chip Devices

Flip-chip hybridization, also known as bump bonding, is a packaging technique for microelectronic devices that directly connects an active element or detector to a substrate readout face-to-face, eliminating the need for wire bonding. In order to make conductive links between the two parts, a solder material is used between the bond pads on each side. Solder bumps, composed of indium metal, are typically deposited by thermal evaporation onto the active regions of the device and substrate. While indium bump technology has been a part of the electronic interconnect process field for many years and has been extensively employed in the infrared imager industry, obtaining a reliable, high-yield process for high-density patterns of bumps can be quite difficult. Under the right conditions, a moderate hydrogen plasma exposure can raise the temperature of the indium bump to the point where it can flow. This flow can result in a desirable shape where indium will efficiently wet the metal contact pad to provide good electrical contact to the underlying readout or imager circuit. However, it is extremely important to carefully control this process as the intensity of the hydrogen plasma treatment dramatically affects the indium bump morphology. To ensure the fine-tuning of this reflow process, it is necessary to have realtime feedback on the status of the bumps. With an appropriately placed viewport in a plasma chamber, one can image a small field (a square of approximately 5 millimeters on each side) of the bumps (10-20 microns in size) during the hydrogen plasma reflow process. By monitoring the shape of the bumps in real time using a video camera mounted to a telescoping 12 magnifying zoom lens and associated optical elements, an engineer can precisely determine when the reflow of the bumps has occurred, and can shut off the plasma before evaporation or de-wetting takes place

From lab and up : superior and economic heat transfer performance of ionanofluids containing long carbon nanotubes and 1-ethyl-3-methylimidazolium thiocyanate

The optimization of energy systems and the efficiency enhancement of energy conversion processesare still huge challenges. The ionanofluids (INFs) composed of the long multi-walled carbon nanotubes(MWCNTs) and 1-ethyl-3-methylimidazolium thiocyanate ionic liquid ([C 2 C 1 im][SCN]) are innovative sys- tems with proven remarkably enhanced thermal conductivity and attractive rheological characteristics.Therefore, as an extension of our previous study, this work aims to examine the overall heat transfer per- formance of these INFs as working fluids for energy conversion processes and design sustainable energysystems. The new measuring set was designed and constructed to determine the convective heat transfercoefficient and pressure drop during the flow of INFs, using the heat exchanger with saturated steam at100 °C. The obtained results showed that the heat transfer of INFs is prevailed by the convection mecha- nism. According to a new thermo-economic efficiency-price index proposed in this work, the amalgama- tion of MWCNTs with [C 2 C 1 im][SCN] is justified from both thermophysical and economic points of view