Wetting of Laser Textured Cu Surface by Ethylene Glycol and Sn

The effect of microcosmic morphologies of textured Cu surface by nanosecond laser on the inert wetting and reactive wetting, i.e., ethylene glycol/copper and tin/copper wetting systems, was studied by using modified sessile drop methods. To create different surface roughness, the microcosmic morphologies with different spacing of grooves were constructed by nanosecond laser. The results showed that the inert wetting (ethylene glycol/copper) was consistent with Wenzel model, while the reactive wetting results deviated from the model. In Sn/Cu reactive wetting system, the interfacial evolution in the early stage and the pinning of triple line by the precipitated h-Cu6Sn5 caused the rougher surface and the worse final wettability. When the scale of artificial roughness exceeded the roughness that was caused by interfacial reaction after reaching the quasi-equilibrium state at interface, the final wettability could be improved.

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Wettability and Interfacial Characteristic of Sn-Ag-Cu Solder on Ni Substrates at Elevated Temperatures

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.554-556.703 ◽

2012 ◽

Vol 554-556 ◽

pp. 703-708

Author(s):

Li Kun Zang ◽

Zhang Fu Yuan Yuan ◽

Hong Liang Yan ◽

Xin Xue Li

Keyword(s):

Integrated Circuits ◽

Elevated Temperatures ◽

Sessile Drop ◽

Triple Line ◽

Contact Angles ◽

Sessile Drop Method ◽

Reactive Wetting ◽

Ni Substrate ◽

Eds Analysis ◽

Interfacial Characteristic

Wettability and interfacial characteristic of the Sn-3.0Ag-0.5Cu/Ni system are investigated by sessile drop method at the temperature range of 503~673K. The reactive wetting processes demonstrate that: contact angles between the solder and Ni substrate decrease as exponential decay and the equilibrium contact angles decrease monotonously with the temperature increasing. Triple-line mobility is enhanced as the temperature increases. Interface of the Sn-3.0Ag-0.5Cu /Ni interface are identified by EPMA and EDS analysis as (Cu,Ni)6Sn5 adjacent to the solder and Ni3Sn4 adjacent to the Ni substrate, respectively. Cu is condensed at the interface, the composition of (Cu,Ni)6Sn5 is (23.16~23.46)Ni- (36.56~37.52) Cu-(39.02~40.27)Sn (atom %). The formation of the (Cu,Ni)6Sn5 IMC was known to greatly improve the reliability of the solder joints in integrated circuits.

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Wetting Behavior and Interfacial Characteristic of the Sn-3.5Ag Alloy on Ni Substrates

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.834-836.335 ◽

2013 ◽

Vol 834-836 ◽

pp. 335-339

Author(s):

Li Kun Zang ◽

Hong Liang Yan ◽

Zhang Fu Yuan ◽

Li Ying Lu

Keyword(s):

Integrated Circuits ◽

Sessile Drop ◽

Triple Line ◽

Contact Angles ◽

Sessile Drop Method ◽

Reactive Wetting ◽

Wetting Behavior ◽

Ni Substrate ◽

Eds Analysis ◽

Interfacial Characteristic

Wetting behavior and interfacial characteristic of the Sn-3.5Ag/Ni system are investigated by sessile drop method at the temperature range of 523~773K. The reactive wetting processes demonstrate that: contact angles between the solder and Ni substrate decrease as exponential decay and the equilibrium contact angles decrease monotonously with the temperature increasing. Triple-line mobility is enhanced as the temperature increases. Compositions of the Sn-3.5Ag/Ni interface are identified by EPMA and EDS analysis as Ni3Sn4adjacent to the solder and Ni3Sn adjacent to the Ni substrate, respectively. The formation of the interface IMC was known to greatly improve the reliability of the solder joints in integrated circuits.

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Investigation of Multiparameter Laser Stripping of AlTiN and DLC C Coatings

Materials ◽

10.3390/ma14040951 ◽

2021 ◽

Vol 14 (4) ◽

pp. 951

Author(s):

Tomáš Primus ◽

Josef Hlavinka ◽

Pavel Zeman ◽

Jan Brajer ◽

Martin Šorm ◽

...

Keyword(s):

Surface Roughness ◽

High Efficiency ◽

Steel Substrate ◽

Cutting Tools ◽

High Hardness ◽

Working Time ◽

Nanosecond Laser ◽

Altin Coating ◽

Successful Removal ◽

Frequency Laser

The lifetime and properties of cutting tools and forming moulds can be prolonged and enhanced by the deposition of hard, thin coatings. After a certain period of usage, the coating will deteriorate. Any remaining coating must be removed prior to successful recoating. Laser stripping is a fast and environmentally friendly coating removal method. In this paper, we present laser removal of two types of coatings deposited on a 1.2379 tool steel substrate, namely, an AlTiN coating with high hardness and a DLC C coating with a small coefficient of friction (COF). A powerful nanosecond laser was employed to remove the coating from the substrate with high efficiency, along with suitable residual surface roughness. Measurements were taken of surface roughness, removed depth, and working time on a stripped area of 1 cm2. The samples were evaluated under a microscope, with a 3D profilometer, and by EDS chemical analysis. Successful removal of the coating was confirmed by optical analysis, but detailed chemical characterisation showed that about 30% of the coating element may remain on the surface. Moreover, a working time of less than 7.5 s per cm2 was obtained in this study. In addition, it was shown that the application of a second low energy, high frequency laser beam pass leads to remelting of the peaks of the material and reduced surface roughness.

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Enhancement of reflection and backscattering components by plane wave imaging for estimation of surface roughness

Japanese Journal of Applied Physics ◽

10.35848/1347-4065/ac4682 ◽

2021 ◽

Author(s):

Kazuhiro Tochigi ◽

Ryo Nagaoka ◽

Jens Erik Wilhjelm ◽

Hideyuki Hasegawa

Keyword(s):

Surface Roughness ◽

Plane Wave ◽

Arterial Wall ◽

Early Stage ◽

Mean Value ◽

Luminal Surface ◽

Ultrasonic Echo ◽

Wave Imaging ◽

The Mean ◽

Reflection Component

Abstract In the early stage of atherosclerosis, the luminal surface of the arterial wall becomes rough. Methods for distinguishing between the reflected and backscattered components in the ultrasonic echo from the arterial wall has the potential to be used as a method for assessment of the roughness of the arterial wall. In this study, we proposed a method to distinguish between the reflected and backscattered components using a technique based on plane wave compounding. This method was evaluated by experiments using planar phantoms with rough surfaces made of polyurethane rubber. The coefficient of variation calculated from the mean value of the reflection component and the standard deviation of the backscattering component was proportional to the roughness of the rubber phantom. This result shows the potential usefulness of this method for analyzing surface roughness of the arterial wall.

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Time-dependent changes in kidney histopathology in ethylene glycol poisoning

Medicine Science and the Law ◽

10.1177/0025802418795352 ◽

2018 ◽

Vol 58 (4) ◽

pp. 257-260 ◽

Cited By ~ 1

Author(s):

Janos Bokor ◽

Krisztina Danics ◽

Eva Keller ◽

Zoltan Szollosi

Keyword(s):

Epithelial Cells ◽

Basement Membrane ◽

Ethylene Glycol ◽

Calcium Oxalate ◽

Early Stage ◽

Time Dependent ◽

Calcium Oxalate Crystals ◽

Oxalate Crystals ◽

Cellular Debris ◽

Tubular Lumen

Ethylene glycol (EG) may be acutely toxic following ingestion. In fatal cases, microscopic examination of urine and kidney specimens can establish a post-mortem diagnosis of EG poisoning. We describe the main renal histopathologic changes during different stages of EG poisoning, which might be helpful when dating the EG poisoning itself. A single-centre retrospective study conducted on all EG poisoning cases demonstrated that in an early stage of EG poisoning, fine dust-like crystals were deposited to the tubular cell basement membrane, followed by internalisation of calcium oxalate crystals into the epithelial cells. Later, the crystals formed larger aggregates within the epithelial cells. As the changes became advanced, pronounced tubular epithelial damage occurred, with detachment of epithelial cells from the basement membrane. In the final stage, coarse calcium oxalate crystals were recognised in the tubular lumen, with cellular debris from damaged epithelial cells. Our study shows that the time-dependent histological changes described follow the clinical stages of EG poisoning and may therefore provide a rough estimate of the time of EG ingestion before death.

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Wettability and Infiltration of Liquid Silicon on Graphite Substrates

Metals ◽

10.3390/met9030300 ◽

2019 ◽

Vol 9 (3) ◽

pp. 300 ◽

Cited By ~ 1

Author(s):

Almudena Casado ◽

Jose Torralba ◽

Srdjan Milenkovic

Keyword(s):

Sessile Drop ◽

Triple Line ◽

Passive Layer ◽

Sessile Drop Method ◽

Purification Process ◽

Key Factors ◽

Vacuum Refining ◽

New Methods ◽

Solar Silicon ◽

Infiltration Behavior

The energy crisis has stimulated a rapid growth of developments in the photovoltaic industry in recent years. To reduce the high cost and the toxicity of classical metallurgical routes, new methods, such as vacuum refining of silicon, have been developed. Moreover, at the industry level, parameters such as the porosity in crucibles and dies are not controlled, so wettability, infiltration, and reaction between silicon and graphite are the key factors in the purification process. In this work, the behavior of several refractory substrates against melted silicon was studied by the classic sessile drop method. The most important phenomena, i.e., wettability and infiltration, were compared with the properties of the substrates. According to the results, for the carbonaceous materials, the reaction of triple line silicon-graphite manages these phenomena, whereas for alumina, a passive layer is formed due to the presence of oxygen, which is subsequently eliminated by the chemical reactions, delaying the process. Regarding the contact angle and infiltration behavior, alumina showed the best results, but due to its reactivity, it contaminates Si, so that this material is not recommended for solar silicon application. However, composite 2 is compatible with the application, as it shows good results in comparison with the other materials.

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A Method for Measuring Contact Angle and the Influence of Surface-Fluid Parameters on the Boiling Heat Transfer Performance

Journal of Heat Transfer ◽

10.1115/1.4047057 ◽

2020 ◽

Vol 142 (9) ◽

Author(s):

Alex P. da Cunha ◽

Taye S. Mogaji ◽

Reinaldo R. de Souza ◽

Elaine M. Cardoso

Keyword(s):

Heat Transfer ◽

Surface Roughness ◽

Contact Angle ◽

Heat Transfer Performance ◽

Sessile Drop ◽

Pool Boiling ◽

Transfer Performance ◽

Transfer Coefficients ◽

Experimental Apparatus ◽

Boiling Process

Abstract An experimental apparatus and a computational routine were developed and implemented in order to obtain the sessile drop images and the contact angle measurement for different fluids and surface conditions. Moreover, experimental results of heat transfer coefficients (HTCs) during pool boiling of de-ionized water (DI water), Al2O3-DI water- and Fe2O3-DI water-based nanofluids are presented in this paper. Based on these results, the effect of surface roughness and nanofluid concentration on the surface wettability, contact angle, and the heat transfer coefficient was analyzed. The experiments were performed on copper heating surfaces with different roughness values (corresponding to a smooth surface or a rough surface). The coated surfaces were produced by the nanofluid pool boiling process at two different volumetric concentrations. All surfaces were subjected to metallographic, wettability and roughness tests. For smooth surfaces, in comparison to DI water, heat transfer enhancement up to 60% is observed for both nanofluids at low concentrations. As the concentration of the nanofluid increases, the surface roughness increases and the contact angle decreases, characterizing a hydrophilic behavior. The analyses indicate that the boiling process of nanofluid leads to the deposition of a coating layer on the surface, which influences the heat transfer performance in two-phase systems.

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