• Journal of Mechanical Science and Technology
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• v.18 no.12
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• pp.2294-2302
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• 2004

The objective of this study is to obtain detailed information for the micro fabrication of lead frames by applying spray technology to wet etching process. Wet etching experiments were performed with different etching parameters such as injection pressure, distance from nozzle tip to etched substrate, nozzle pitch and etchant temperature. The characteristics of single and twin spray were measured to investigate the correlation between the spray characteristics and the etching characteristics. Drop size and velocity were measured by Phase-Doppler Anemometer (PDA). Four liquids of different viscosity were used to reveal the effects of viscosity on the spray characteristics. The results indicated that the shorter the distance from nozzle tip and the nozzle pitch, the larger etching factor became. The average etching factor had good positive correlation with average axial velocity and impact force. It was found that the etching characteristics depended strongly on the spray characteristics.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.1
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• pp.73-78
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• 2007

The objective of this work was to simulate lead frame etching characteristics to optimize the etching process, Characteristics such as the etching factor and uniformity were investigated for different actual operating conditions, including pressure, distance from the nozzle tip, pipe pitch, and feed speed. The correlation between the etching and spray characteristics was analyzed to develop the etching model. Spray characteristics obtained from an experiment using a phase Doppler anemometer system were then simulated using a Monte-Carlo technique, The etching process model was coded in the Java language, The spray and etching characteristics were correlated with each other and simulated results agreed well with the measured data for a lead frame etching process, The optimal operating parameters under various conditions were successfully determined.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.1
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• pp.109-117
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• 2004

The objective of this study is to investigate the effect of the spray characteristics on the etching characteristics for the optimization of etching process in the micro fabrication industry. The etching characteristics such as etching rate and etching factor were investigated under different etching conditions. To compare with the etching characteristic, the spray characteristics such as droplet size and velocity were measured by PDA system. The etching rate was increased in case of high spray pressure and in the region of spray center. The etching factor was increased with decrease in the distance from nozzle tip and increase in the etchant temperature. It was found that the spray characteristics were correlated with the etching characteristics.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.7
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• pp.842-849
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• 2004

The objective of this work is to study the improvement of etching characteristics in wet etching process. The etching characteristics such as etching factor were investigated under different etching conditions and compared with the spray characteristics. The spray characteristics of nozzle with different geometries such as swirler angle and swirl chamber aspect ratio were analyzed by using PDA system to predict the effect of the spray characteristics on the etching factor. The swirler angles were 49,5$^{\circ}$, 63$^{\circ}$ and 76.5$^{\circ}$. The swirl chamber aspect ratios were 1.2, 1.6 and 2.0. It was found that the etching factor was correlated with the spray characteristics and also the smaller swiller angle, the larger etching factor became.

• Transactions on Electrical and Electronic Materials
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• v.16 no.4
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• pp.169-172
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• 2015

Although, there are several research studies on the engineering of the graphene layers using different etching techniques, there is not any comprehensive study on the effects of using different etching masks in the reactive ion etching (RIE) method on the quality and uniformity of the etched graphene films. This study investigated the effects of using polystyrene and conventional photolithography resist as a etching mask on the engineering of the number of graphene layers, using RIE. The effects were studied using Raman spectroscopy. This analysis indicated that the photo-resist mask is better than the polystyrene mask because of its lower post processing effects on the graphene surface during the RIE process. A single layer graphene was achieved from a bi-layer graphene after 3 s of the RIE process using oxygen plasma, and the bi-layer graphene was successfully etched after 6 s of the RIE process. The bilayer etching time was significantly smaller than reported values for graphene flakes in previous research.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.4
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• pp.449-455
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• 2004

The objective of this study is to obtain the correlation between the spray characteristics and the etching characteristics for the optimization of etching system in the micro fabrication industry. The etching characteristics such as etching rate were measured under different conditions. The single spray characteristics such as droplet size and velocity were measured by PDA system. These were compared to the etching characteristics. The twin spray characteristics in the overlap region were analyzed to predict the effect of them on the etching characteristics with the pitch and also were compared to the single spray. The etching rate was increased in case of high spray pressure and in the region of spray center. It was found that the etching characteristics could be correlated with the single spray characteristics and the twin spray characteristics were correlated with the etching characteristics.

• Fashion & Textile Research Journal
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• v.3 no.4
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• pp.344-350
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• 2001

Wool fabrics were treated with dichloro isocyanuric acid (DCCA) and dyed with acid dyes (C.I. Acid Red 18), and then, they were treated by sputter etching. Wool fabrics had been sputtered with aluminium under various conditions such as sputter etching time and discharge power in the presence of argon gas. We compared mechanical properties, colour difference and fastness properties of these samples one another: Mechanical properties and colour difference of sputtered wool fabrics changed by sputter etching time, discharge power and DCCA concentration. Light fastness showed a rising tendency but rubbing fastness showed a downward tendency when sputter etching time was 7 minutes.

• Journal of Sensor Science and Technology
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• v.30 no.1
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• pp.10-14
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• 2021

Wet etching is more economical than dry etching and provides a uniform etching depth regardless of wafer sizes. Typically, potassium hydroxide (KOH) and tetra-methyl-ammonium hydroxide (TMAH) solutions are widely used for the wet etching of silicon. However, there is a limit to the wet etching process when a material deposited on an unetched surface reacts with an etching solution. To solve this problem, in this study, an apparatus was designed and manufactured to physically block the inflow of etchants on the surface using a rubber O-ring. The proposed apparatus includes a heater and a temperature controller to maintain a constant temperature during etching, and the hydrostatic pressure of the etchant is considered for the thin film structure. A corrugation membrane with a diameter of 800 ㎛, thickness of 600 nm, and corrugation depth of 3 ㎛ with two corrugations was successfully fabricated using the prepared device.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.4 s.247
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• pp.381-388
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• 2006

The objective of this study is to predict the etching characteristics using spray characteristics for the optimization on the etching process of Lead-Frame. The etching characteristics such as etching factor, uniformity were investigated on the actual operating conditions. The correlation between the etching characteristics and the spray ones obtained by measurement were analyzed to simulate the etching characteristics according to actual conditions of lead-frame etching process. These conditions of lead-frame process were spray pressure, distance from nozzle tip to substrate, pipe pitch, and nozzle pitch. To improve the etching characteristics in the lead-frame process, effects of the various operating conditions should be understood in detail. The spray characteristics obtained by experiment using PDA system were simulated by the Monte-Carlo method. The etching process model was coded by Java language. It was found that simulation results generally agreed well with the measured results of etching characteristics in lead-frame etching process. The optimal operating parameters were successfully found under variable conditions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.12
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• pp.1911-1918
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• 2001

Recently the non-destructive test technique which uses the grain boundary etching characteristics owing to the variation of material structures has been proposed. However, during in-serviced GEM test there are a lot of variables such as the changes of temperature and concentration of etching solution, the roughness condition of surface polished etc.. The purpose of this paper is to investigate the influences of these test variables on GEM test results in order to establish a reliable and sensitive of GEM evaluation technique. The experiments are conducted in various solution temperatures, 10$\^{C}$, 15$\^{C}$, 20$\^{C}$, and 25$\^{C}$ and in 70% and 100% concentrations of that, and in various surface roughnesses polished by #800, #2000, and 0.3㎛ alumina powder. Through the test with variables, it is verified that the decrease of temperature and concentration of etching solution and the coarsened surface roughness by not using polishing cloth and powder induce some badly and/or greatly influences on GEM test results like grain boundary etching width(W$\_$GB) and intersecting point ratio(N$\_$i/N$\_$0/). Therefore, to get reliable and good GEM test results, it must be prepared the surface of specimen polished by polishing cloth and 0.3㎛ alumina powder and the saturated picric acid solution having 25$\^{C}$ and be maintained the constant temperature(25$\^{C}$) during GEM test.