Study on Condensation Heat Transfer of Micro Structured Surfaces (Effect on Condensation Heat Transfer of Metal-Spattering Surfaces)

2011 ◽  
Author(s):  
Takeru Komatsu ◽  
Hiroyasu Ohtake ◽  
Yasuo Koizumi
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Silicon Surface ◽  
Copper Surface ◽  
Metal Films ◽  
Thin Metal ◽  
Condensation Heat Transfer ◽  
Silicon Surfaces ◽  
Thin Metal Films ◽  
Structured Surfaces

The present study was intended to examine how the condensation heat transfer, especially the drop-wise condensation, was affected by modifying the surface nature. In the present study, condensation heat transfer experiments for steam were performed by using mirror-finished copper surface, mirror-finished silicon surface and some mirror-finished silicon surfaces with very thin metal films by using spattering. The silicon surfaces with the thin metal films were created by the MEMS technology. The film- and also the drop-wise condensation were observed on the copper surface. The filmwise condensation heat flux was in good agreement with the values of the Nusselt’s equation. It was approximately one-tenth of the drop-wise condensation heat flux. The condensation on the mirror-finished silicon surface was the drop-wise condensation. The heat flux was approximately one-tenth of the drop-wise condensation heat flux on the copper surface. The condensation on silicon surfaces with thin Copper (Cu), Chromium (Cr), Lead (Pb) and Gold (Au) films were drop-wise. The condensation on silicon surfaces with thin Nickel (Ni), Titanium (Ti) and Aluminum (Al) films were filmwise.

Study on Condensation Heat Transfer of Micro Structured Surfaces

2009 ◽  
Author(s):  
Hiroyasu Ohtake ◽  
Yasuo Koizumi ◽  
Soichiro Miyake
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Surface Film ◽  
Copper Surface ◽  
Heat Fluxes ◽  
Condensation Heat Transfer ◽  
Silicon Surfaces ◽  
Copper Surfaces ◽  
Structured Surfaces ◽  
Mems Technology

Condensation heat transfer experiments for steam were performed by using mirror-finished copper surfaces, mirror-finished silicon surfaces and silicon surfaces with micro grooves or micro pins on it. The micro-grooves and the micro-pins were created by the MEMS technology. The film- and also the drop-wise condensation were observed on the copper surface. The film-wise condensation heat flux was in good agreement with the values of the Nusselt equation. It was approximately one-tenth of the drop-wise condensation heat flux. The condensation on the mirror-finished silicon surface was the drop-wise condensation. The heat flux was approximately one-tenth of the drop-wise condensation heat flux on the copper surface. The condensation on the micro-grooved and the micro-pin silicon surfaces was film-wise. The condensation heat fluxes were approximately one-tenth of the copper surface film-wise condensation heat flux. When the contact angle was smaller than 70 degree, the condensation was film-wise and when larger than the value, drop-wise. It seemed that the hollow parts of the micro-grooved or the micro-pin surface were filled with condensate first after the condensation was initiated. It made the surface hydrophilic and the condensation film-wise.

Study on Condensation Heat Transfer on Micro Structured Surfaces (Effect on Condensation Heat Transfer of Metal Sputtering Surfaces)

2013 ◽  
Author(s):  
Kohei Yamazaki ◽  
Hiroyasu Ohtake ◽  
Koji Hasegawa
Keyword(s):  
Heat Transfer ◽  
Metal Film ◽  
Copper Surface ◽  
Thin Metal Film ◽  
Thin Metal ◽  
Condensation Heat Transfer ◽  
Dropwise Condensation ◽  
Transfer Coefficients ◽  
Structured Surfaces ◽  
Heat Transfer Coefficients

The present study was intended to examine how the condensation heat transfer, especially the dropwise condensation, was affected by modifying the surface nature. In the present study, condensation heat transfer experiments for steam were performed by using mirror-finished copper surface and some very thin metal-film surfaces by using sputtering on mirror-finished copper block. That is, the effects on pattern of condensation heat transfer, i.e., dropwise or film-wise condensation, of metal-sputtered surfaces were examined experimentally and qualitatively. The present experimental results showed that the condensation on sputtered metal surfaces of Copper (Cu), Chromium (Cr) and Lead (Pb), became dropwise condensation. The heat transfer coefficients were ten times higher than the Nusselt equation. The condensation on sputtered metal surface of Titanium (Ti) became filmwise condensation. High contact angle was trended to be dropwise condensation on very thin metal-film surfaces by using sputtering.

scholarly journals Femtosecond Laser Pulse Train Effect on Optical Characteristics and Nonequilibrium Heat Transfer in Thin Metal Films

2010 ◽  
Vol 51 (6) ◽  
pp. 1156-1162 ◽  
Author(s):  
Hyung Sub Sim ◽  
Seungho Park ◽  
Tae-Hyoung Kim ◽  
Young Ki Choi ◽  
Joon Sik Lee ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Laser Pulse ◽  
Femtosecond Laser ◽  
Femtosecond Laser Pulse ◽  
Pulse Train ◽  
Metal Films ◽  
Thin Metal ◽  
Optical Characteristics ◽  
Thin Metal Films

Investigation of Flow Boiling on Nanostructured Surfaces

2010 ◽  
Author(s):  
Saeil Jeon ◽  
Pratanu Roy ◽  
N. K. Anand ◽  
Debjyoti Banerjee
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Silicon Surface ◽  
High Speed ◽  
Flow Boiling ◽  
Copper Surface ◽  
Heat Fluxes ◽  
Test Fluid ◽  
Nanostructured Surfaces ◽  
Layer Effect

Flow boiling experiments were performed on copper, bare silicon and carbon nanotube (CNT) coated silicon wafer using water as the test fluid. Wall heat flux was measured by varying the wall superheat. The experiments were performed under pool boiling conditions (zero flow rate) as well as by varying the flow rates of water. The liquid sub-cooling was varied between 40 ∼ 60 °C. An infra–red camera was used to calibrate the surface temperature of the silicon wafers and the copper surface. Heat flux measurements were performed by using a calorimeter apparatus. High speed visualization experiments were performed to measure the bubble departure diameter, bubble departure frequency and bubble growth rate as a function of time. Heat flux values for all three surfaces were calculated from the temperature differences obtained by sheathed thermocouples inside the copper block in the calorimeter apparatus. Flow boiling curves were plotted to enumerate the enhancements in heat transfer. It was observed that MWCNT coated silicon surface enables higher heat fluxes compared to bare silicon surface. This enhancement can be ascribed to be due to the high thermal conductivity of the carbon nanotubes, micro-layer effect, enhancement of transient heat transfer due to periodic solid-liquid contact and increase in active nucleation sites on nanostructured surfaces.

Metal Microstructures in Advanced CMOS Devices

1996 ◽  
Vol 54 ◽  
pp. 358-359
Author(s):  
L. M. Gignac ◽  
K. P. Rodbell
Keyword(s):  
Grain Boundaries ◽  
Semiconductor Device ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Metal Films ◽  
Thin Metal ◽  
Electrical Performance ◽  
Thin Metal Films ◽  
Chemical Vapor Deposited ◽  
Boundary Properties

As advanced semiconductor device features shrink, grain boundaries and interfaces become increasingly more important to the properties of thin metal films. With film thicknesses decreasing to the range of 10 nm and the corresponding features also decreasing to sub-micrometer sizes, interface and grain boundary properties become dominant. In this regime the details of the surfaces and grain boundaries dictate the interactions between film layers and the subsequent electrical properties. Therefore it is necessary to accurately characterize these materials on the proper length scale in order to first understand and then to improve the device effectiveness. In this talk we will examine the importance of microstructural characterization of thin metal films used in semiconductor devices and show how microstructure can influence the electrical performance. Specifically, we will review Co and Ti silicides for silicon contact and gate conductor applications, Ti/TiN liner films used for adhesion and diffusion barriers in chemical vapor deposited (CVD) tungsten vertical wiring (vias) and Ti/AlCu/Ti-TiN films used as planar interconnect metal lines.

On the electrocatalytic symbiotic synergism between Pt, Ni and Al in plasma vapour deposited PtxNiyAlz thin metal films for water electrolysis

2021 ◽  
Vol 494 ◽  
pp. 229344
Author(s):  
Roelof J. Kriek ◽  
Liesel A. van Heerden ◽  
Anzel Falch ◽  
Malcolm I. Gillespie ◽  
Alaa Y. Faid ◽  
...  
Keyword(s):  
Water Electrolysis ◽  
Metal Films ◽  
Thin Metal ◽  
Thin Metal Films
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