Effect of Microstructure on the Minimum Critical Radius and Critical Number of Gas Atoms for Swelling

2008 ◽  
pp. 481-481-12
Author(s):  
WA Coghlan ◽  
LK Mansur
Keyword(s):  
Critical Radius ◽  
Critical Number ◽  
Effect Of Microstructure

An Investigation on the Profile of Microlens by the Thermal Reflow Process Due to Surface Tension and Gravity

2008 ◽  
Author(s):  
Jhy-Cherng Tsai ◽  
Yong-Sung Hsu
Keyword(s):  
Surface Tension ◽  
Critical Radius ◽  
Critical Size ◽  
Liquid Droplet ◽  
Bond Number ◽  
Diameter Ratio ◽  
Experimental Result ◽  
Critical Number ◽  
Reflow Process ◽  
Thermal Reflow

Microlens and its mold fabricated by thermal reflow using photoresist have been widely used for forming patterns in different scales. When the photoresist solidifies from melting condition, for example by the reflow process, its profile is formed based on the balance between surface tension and gravity. This research is aimed to investigate the influence of surface tension and gravity on the profile of microlens in thermal reflow process. Theoretical analysis based on the interaction between surface tension and gravity of liquid droplet is first investigated. The result showed that the height to diameter ratio (h/D), or the sag ratio, of the liquid droplet is affected by the Bond number (Bo), a number defined as the ratio of gravity to surface tension. The sag ratio is not sensitive to Bo when Bo is small but the ratio decreases as Bo increases if Bo is over the critical number. Based on the analysis, the critical number for the AZ4620 photoresist on a silicon substrate is 1, corresponding to the critical radius of droplet R = 2,500μm. When the size of the droplet is less then the critical size, the profile is mainly controlled by the surface tension and thus the sag ratio is about the same regardless the size. The profile, in contrast, is highly affected by the gravity if the size of the droplet is larger then the critical size. The sag ratio decreases exponentially with respect to Bo in this case. Experiments are also designed and conducted to verify the analysis. Experimental result showed that the sag ratio of the photoresist reduces to 0.065 from 0.095 when Bo increases from 0.0048 to 0.192. The results showed that the trend is consistent to the theoretical model.

The Effect of Microstructure and Welding-Induced Plasticity on the Strength of Ni–Mo–Cr Alloy Welds

2020 ◽  
Author(s):  
Alexander E. Danon ◽  
O. Muránsky ◽  
Hanliang Zhu ◽  
T. Wei ◽  
Emmanuel Alejandro Flores-Johnson ◽  
...  
Keyword(s):  
Effect Of Microstructure

scholarly journals Seismic Dispersion and Attenuation in Fluid‐Saturated Carbonate Rocks: Effect of Microstructure and Pressure

2019 ◽  
Vol 124 (12) ◽  
pp. 12498-12522 ◽  
Author(s):  
Jan V. M. Borgomano ◽  
Lucas X. Pimienta ◽  
Jérôme Fortin ◽  
Yves Guéguen
Keyword(s):  
Carbonate Rocks ◽  
Dispersion And Attenuation ◽  
Effect Of Microstructure

Monocrystalline Fiber Growth Technique: New Critical Radius Considerations

2021 ◽  
pp. 126199
Author(s):  
Jorge-Enrique Rueda-P ◽  
J.E.F.S. Rodrigues ◽  
Antonio Carlos Hernandes
Keyword(s):  
Critical Radius ◽  
Growth Technique ◽  
Fiber Growth
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