• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.1058-1062
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• 1997

Development of laser induced chemical etching technologt with KrF laser are carried out in this study for micromachining of silicon wafer. The paper is devoted to experimental identification of excimer laser induced mechanism of silicon under chlorine pressures(0.02~500torr). Experimental results on pulsed KrF excimer laser etching of silicon in chorine atmosphere are presented. Etching rate dependency on laser fluence and chlorine pressure are discussed on the basis of experimental analysis, it is concluded that accurate digital micro machining process of silicon wafer can achieved by KrF laser induced chemical etching technology.

• Proceedings of the Optical Society of Korea Conference
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• 1997.08a
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• pp.96-96
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• 1997

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.235-236
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.151-152
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• 2011

• Journal of the Korean Society for Precision Engineering
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• v.17 no.7
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• pp.28-28
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• 2000

• Journal of the Korean Society for Precision Engineering
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• v.17 no.7
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• pp.27-35
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• 2000

재료가공분야에의 레이저의 적용은 1960년대 후반부터 시작되었으며, 고출력 CO$_2$ 와 Nd:YAG 레이저가 많은 산업분야에서 보편화될 정도로 발전하여 왔다. 재료가공에서의 레이저의 적용분야는 금속의 절단, 용접 및 드릴링, 세라익의 스크라이빙, 플라스틱과 복합재의 절단 및 여러 가지 재료의 마킹 등을 포함한다. 이와 같은 모든 응용에서 공통적인 것이 레이저 조사에 의해 재료를 용융, 증발시키는 열적 메카니즘이다.(중략)

• Journal of the Korean Society for Precision Engineering
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• v.26 no.6
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• pp.50-58
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• 2009

Micro laser fabrication techniques can potentially be used for the manufacture of microstructures on the thin flat surfaces with large diameter that are frequently used in semiconductor industries. However, the large size of wafers can cause the degraded machining accuracy of the surface because it can be tilted or distorted by geometric errors of machines or the holding fixtures, etc. To overcome these errors the off-line focusing error compensation method is proposed. By using confocal autofocus system, the focusing error profile of machined surface is measured along the pre-determined path and can be compensated at the next machining process by making the corrected motion trajectories. The experimental results for silicon wafers and invar flat surfaces show that the proposed method can compensate the focusing error within the level of below $6.9{\mu}m$ that is the depth of focus required for the laser micromachining process.

• Design & Manufacturing
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• v.14 no.3
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• pp.44-49
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• 2020

One of display trends today is development of high pixel density. To get high PPI, a small size of pixel must be developed. RGB pixel is arranged by evaporation process which determines pixel size. Normally, a fine metal mask (FMM; Invar alloy) has been used for evaporation process and it has advantages such as good strength, and low thermal expansion coefficient at low temperature. A FMM has been manufactured by chemical etching which has limitation to controlling the pattern shape and size. One of alternative method for patterning FMM is laser micromachining. Femtosecond laser is normally considered to improve those disadvantages for laser micromachining process due to such short pulse duration. In this paper, a femtosecond laser drilling for thickness of 16 ㎛ FMM is examined. Additionally, we introduce experimental results for controlling taper angle of hole by vibration module adapted in laser system. We used Ti:Sapphire based femtosecond laser with attenuating optics, co-axial illumination, vision system, 3-axis linear stage and vibration module. By controlling vibration amplitude, entrance and exit diameters are controllable. Using vibrating objective lens, we can control taper angle when femtosecond laser hole drilling by moving focusing point. The larger amplitude of vibration we control, the smaller taper angle will be carried out.

• Journal of the Optical Society of Korea
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• v.7 no.3
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• pp.166-173
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• 2003

This paper presents micromachining results on planar-lightwave-circuit (PLC) chips with Si substrate and the quartz substrate by using Ti:Sapphire femtosecond-pulsed laser. The ablation process with femtosecond laser pulses generates nothing of contamination, molten zone, microcracks, shock wave, delamination and recast layer. We also showed that the micromachine for PLC using femtosecond pulsed lasers is superior to that using nanosecond pulsed lasers. The insertion loss and the optical return loss of the 1 ${\times}$ 8 optical power splitters packaged with micromachined input- and output-port U-grooves were less than 11.0 ㏈ and more than 55 ㏈, respectively. The wavelength dependent loss (WDL) was distributed within $\pm$0.6 ㏈ and the polarization dependent loss (PDL) was less than 0.2 ㏈.

• Proceedings of the Optical Society of Korea Conference
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• 2007.07a
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• pp.71-72
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• 2007