High-speed microprobe for roughness measurements in high-aspect-ratio microstructures

The results of numerical studies carried out on high-aspect-ratio wings with different planforms are discussed: the transonic regime is analysed for a swept wing and a curved planform wing. The wings have similar aspect ratios and similar aerodynamic profiles. The analyses were carried out by CFD and FE techniques, and the reliability of the numerical aerodynamic results was proven by a sensitivity study. Analysing the performances of the two wings demonstrated that in transonic flight conditions, a noticeable drag reduction can be obtained by adopting a curved planform wing. In addition, for such a wing, the aeroelastic instability condition, consisting in a classical flutter, is postponed compared to a conventional swept wing, for which a flutter-buffet instability occurs. In a preliminary manner, the study shows that, for a curved planform wing, the high speed buffet is not an issue and at the same time notable fuel saving can be achieved.

Download Full-text

A Study on the Characteristics of Micro Deep Hole Machining Processes

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.364-366.566 ◽

2007 ◽

Vol 364-366 ◽

pp. 566-571

Author(s):

Tae Il Seo ◽

Dong Woo Kim ◽

Myeong Woo Cho ◽

Eung Sug Lee

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

High Speed ◽

Printed Circuit Boards ◽

Hole Drilling ◽

Deep Hole ◽

Machining Processes ◽

Deep Hole Drilling ◽

Micro Drilling ◽

Hole Machining

Recently, the trends of industrial products move towards more miniaturization, variety and mass production. Micro drilling which take high precision in cutting work is required to perform more micro hole and high speed working. Especially, Micro deep hole drilling is becoming more important in a wide spectrum of precision production industries, ranging from the production of automotive fuel injection nozzle, watch and camera parts, medical needles, and thick multilayered Printed Circuit Boards(PCB) that are demanded for very high density electric circuitry. The industries of precision production require smaller holes, high aspect ratio and high speed working for micro deep hole drilling. However the undesirable characteristics of micro drilling is the small signal to noise ratios, wandering motion of drill, high aspect ratio and the increase of cutting force as cutting depth increases. In order to optimize cutting conditions, an experimental study on the characteristics of micro deep hole machining processes using a tool dynamometer was carried out. And additionally, microscope with built-in an inspection monitor showed the relationship between burr in workpieces and chip form of micro drill machining.

Download Full-text

Deep Etching of Single- and Polycrystalline Silicon with High Speed, High Aspect Ratio, High Uniformity, and 3D Complexity by Electric Bias-Attenuated Metal-Assisted Chemical Etching (EMaCE)

ACS Applied Materials & Interfaces ◽

10.1021/am504046b ◽

2014 ◽

Vol 6 (19) ◽

pp. 16782-16791 ◽

Cited By ~ 36

Author(s):

Liyi Li ◽

Xueying Zhao ◽

Ching-Ping Wong

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

Chemical Etching ◽

Polycrystalline Silicon ◽

High Speed ◽

Deep Etching ◽

High Uniformity ◽

Metal Assisted Chemical Etching

Download Full-text

Enabling Robust Copper Fill of High Aspect Ratio Through Silicon Vias

International Symposium on Microelectronics ◽

10.4071/isom-2010-tp1-paper3 ◽

2010 ◽

Vol 2010 (1) ◽

pp. 000176-000179

Author(s):

Mark Willey ◽

Damo Srinivas ◽

Sesha Varadarajan ◽

David Porter ◽

Easwar Srinivasan ◽

...

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

High Speed ◽

High Performance ◽

Process Window ◽

Seed Technology ◽

Aspect Ratios ◽

Reducing Costs ◽

Electroplating Process ◽

Silicon Vias

Today's Through Silicon Via (TSV) processes are limited to aspect ratios of 10:1. High performance logic devices drive the need for aspect ratios approaching 20:1 in order to achieve the desired performance while simultaneously reducing costs. The reduced via area required on the wafer enables the designer to utilize less real estate on the die to reduce cost or to potentially add redundant vias to improve yield. However, current conventional processes and techniques are not capable of achieving robust fill on aspect ratios greater than 12:1. This presentation will highlight the technical challenges in achieving robust copper fill on super high aspect ratio TSV structures. Additionally, a compelling, economic solution pathway will be presented that integrates a low temperature conformal high quality dielectric isolation layer, a high step coverage Cu barrier / seed technology and a void free high speed electroplating process with a wide process window that could accelerate the adoption of the high aspect ratio TSV design schemes.

Download Full-text

Experimental Investigation of the Evaporation and Stability of a Meniscus in a Flat Microchannel

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.312-315.1178 ◽

2011 ◽

Vol 312-315 ◽

pp. 1178-1183

Author(s):

Souad Harmand ◽

Khellil Sefiane ◽

Rachid Bennacer ◽

Nicolas Lancial

Keyword(s):

Experimental Investigation ◽

Aspect Ratio ◽

High Aspect Ratio ◽

High Speed ◽

Evaporation Rate ◽

Liquid Meniscus ◽

Line Region ◽

Three Phase ◽

Increasing Temperature ◽

Insight Into

We present the results of an experimental investigation of the evaporation of a liquid meniscus in a high aspect ratio micro-channel. The study investigates evaporation rates of a stationary liquid meniscus in a high aspect ratio microchannel, the wall of which is electrically heated using transparent resistive coating. Four different liquids are used as working fluids. We report on the dependence of the measured overall evaporation rate on the applied power. The results indicate, and consistently, that the evaporation rate increases with the applied power then peaks before declining. In order to gain insight into these results, we used thermographic infra red imaging to map the temperature field on the external wall of the microchannel. The measurements show that there is a good correlation between the maximum in the evaporative rate and the onset of instabilities of the interface. These instabilities, to our mind, are induced by an increasing temperature gradient along the microchannel wall around the three phase contact line region. These instabilities are revealed by a high speed camera used to record the behaviour of the interface during evaporation.

Download Full-text

Ultra-high-speed cantilever tactile probe for high-aspect-ratio micro metrology

2015 Transducers - 2015 18th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS) ◽

10.1109/transducers.2015.7181109 ◽

2015 ◽

Cited By ~ 2

Author(s):

H.S. Wasisto ◽

L. Doering ◽

U. Brand ◽

E. Peiner

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

High Speed ◽

Ultra High Speed ◽

Tactile Probe

Download Full-text

Machining of Thin Walls and Thin Floor Aerospace Components Made of Aluminum Alloy with High Aspect Ratio

Materials Science Forum ◽

10.4028/www.scientific.net/msf.830-831.112 ◽

2015 ◽

Vol 830-831 ◽

pp. 112-115 ◽

Cited By ~ 1

Author(s):

Anil Kumar Jain ◽

Kasala Narasaiah ◽

Shibu Gopinath

Keyword(s):

Aluminum Alloy ◽

Aspect Ratio ◽

High Aspect Ratio ◽

High Speed ◽

Removal Rate ◽

Dimensional Accuracy ◽

Raw Material ◽

Thin Wall ◽

High Speed Machining ◽

Static And Dynamic Analysis

In present scenario most of airframe components employ aluminum alloy materials having wall thickness of 1.2 to 3mm. With advancement of manufacturing techniques such as high speed machining, it is possible to machine components with wall/floor thickness up to 0.3 to 0.5 mm with high aspect ratio. The aim of making such parts is to reduce weight of payload. The machining of monolithic structure involves removing of material up to 95% from the raw material. The objective of the study is to achieve maximum material removal rate without compromise on geometry, dimensional accuracy while machining the part. This paper proposes a working methodology for high speed machining which includes efficient process planning, based on static and dynamic analysis. This paper provides insight knowledge of selection of cutting tool, fixture design, clamping method, cutting process parameters; machine tool and computer aided manufacturing (CAM) strategy, optimum stock for minimal bending and distortion. This technology has been demonstrated in hexagonal test specimen of 0.5 mm thin wall and also proven on the indigenous developed global positioning system (GPS) components.

Download Full-text