• Design & Manufacturing
• /
• v.14 no.3
• /
• pp.44-49
• /
• 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 Korean Society for Precision Engineering
• /
• v.27 no.6
• /
• pp.7-16
• /
• 2010

Physical fundamentals of ultrashort femtosecond lasers are addressed along with emerging applications for precision manufacturing and metrology. Femtosecond lasers emit short pulses whose temporal width is in the range of less than a picosecond to a few femtoseconds, thereby enabling extremely high peak-power machining with less thermal damages. Besides, the broad spectral bandwidth of femtosecond lasers constructed in the form of frequency comb permits absolute distance measurements leading to ultraprecision positioning control and dimensional metrology.

• Transactions of Materials Processing
• /
• v.15 no.3 s.84
• /
• pp.213-219
• /
• 2006

To improve the strength of glass is being studied in order to contribute to weight saving of flat panel displays. Generally, the strength achieved of glass-ceramics is higher as is the fracture toughness by the formation of a heterogeneous phase inside glass. In this study, Ag-doped $45SiO_2-24CaO-24Na_2O-4P_2O_5\;and\;70SiO_2-10CaO-24Na_2O-10TiO_2$ glasses were irradiated to strengthen by crystallization using femto-second laser pulse. XRD, Nano-indenter and SEM etc., irradiation of laser pulse without heat-treated samples was analyzed. Samples irradiated by laser had higher value($4.4{\sim}4.56^*10-3Pa$) of elastic modulus which related with strength of glass than values heat-treated samples and these are $1.2{\sim}1.5$ times higher values than them of mother glass. This process can be applicable to the strengthening of thinner glass plate, and it has an advantage over traditional heat-treatment and ion-exchange method.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.11a
• /
• pp.581-582
• /
• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.10a
• /
• pp.61-62
• /
• 2006

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2011.06a
• /
• pp.869-870
• /
• 2011

• Proceedings of the Optical Society of Korea Conference
• /
• 1998.08a
• /
• pp.66-67
• /
• 1998

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.655-656
• /
• 2006

We will provide the ultra-precise material processing technique with a femtosecond pulse laser system.

• Proceedings of the Optical Society of Korea Conference
• /
• 2003.07a
• /
• pp.248-249
• /
• 2003

The characterization of laser mirrors is important for obtaining proper performance of femtosecond lasers. Characteristics of laser mirrors are usually described in terms of their reflectivity at a certain wavelength. In femtosecond laser applications, however, the dispersion property of the mirror should be considered because the temporal shape of a femtosecond light pulse changes during the reflection at the mirrors. (omitted)

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.1 s.178
• /
• pp.13-22
• /
• 2006