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Full-Text Articles in Mechanical Engineering
Mechanisms And Solutions To The Brittle Solder Joint In Electroless Ni Plating, Xuan Wang, C. Key Chung
Mechanisms And Solutions To The Brittle Solder Joint In Electroless Ni Plating, Xuan Wang, C. Key Chung
Industrial and Manufacturing Engineering
Brittle solder joints in Electroless Ni electroless Pd immersion Au (ENEPIG) surface finishes are one of the key reliability issues in electronics assembly. Previous characterization of the reflow process has indicated that interfacial voids formed after solder reflow are responsible for the decreases in solder joint strength. However, the mechanisms behind the formation of these voids in the ENEPIG process remain unclear. In this paper, the interaction between various aspects of the ENEPIG process and solder joint strength were investigated. Surface roughness, morphology, and nano-pitting at the interface between electroless Pd and Ni-P were characterized. The size and density of …
Densification Of W-Ni-Fe Powders Using Laser Sintering, Xuan Wang, Matthew Wraith, Stephen Burke, Howard Rathbun, Kyle Devlugt
Densification Of W-Ni-Fe Powders Using Laser Sintering, Xuan Wang, Matthew Wraith, Stephen Burke, Howard Rathbun, Kyle Devlugt
Industrial and Manufacturing Engineering
In this paper, Laser Sintering (LS) of 90%W–7%Ni–3%Fe (wt.%) powders have been investigated, with the goal to understand the influence of final density by laser power, scanning speed, laser trace width, and the number of scanning passes. The results suggest that the laser power and scanning speed are the most important factors influencing density; the influence of trace width and number of scanning passes are not significant. With the increase of laser power and decrease of scanning speed, higher density can be achieved. The microstructure analysis indicated that the porosity changed from open porosity to closed porosity with higher laser …