• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.21 no.3
• /
• pp.382-386
• /
• 2012

A femtosecond laser with 775nm central wavelength and 150 fs of temporal pulse width was used for multi layered glass cutting applications. Ultrashort pulse was effectively used for clean glass cutting with $50{\mu}m$ depth and minimum cutting width. Laser beam was split to two stages and focused on the top surfaces of each layer. Ablation threshold of used glass was measured to be $2.59J/cm^2$. In experiments, 200mW laser power and 1mm/s scanning speed was used for preliminary experiment. Air gap was the major defect occurring parameter and laser power was less sensitive to glass cutting in the experiment. The maximum cutting speed was measured to be 60mm/min with 2kHz, however, Maximum 3m/min cutting speed can be achievable with a commercially available laser with 100kHz.

• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.4
• /
• pp.403-408
• /
• 2013

In this paper, the characteristics of ablation processing of the eagle glass by pico-second laser are investigated. The laser ablation is used to process micro forms on materials. The ablation causes little thermal effect and little burr on the surface of eagle glass. In order to examine the characteristics of panic cracks, experiments are conducted under various cutting conditions such as a frequency of 600 kHz, laser powers, scan speeds and number of scan(NS). To minimize the panic cracks, the specimens are heated at $30^{\circ}C$, $45^{\circ}C$, and $60^{\circ}C$ for ten minutes respectively and then they are broken by hands. Laser powers, NS and scan speeds have an effect on glass cutting results. The ablation depths increase with an increase in the laser power and NS whereas the panic cracks decrease with an increase in scan speed. The high temperature on processed specimens reduces the panic cracks and makes good results of laser cutting. The optimal condition for eagle glass laser cutting is found to be at 30 W of laser power, 3 mm/s of scan speed and 500 of NS, respectively.

• Korean Journal of Materials Research
• /
• v.18 no.5
• /
• pp.247-252
• /
• 2008

A laser glass cutting system using a femto-second laser was evaluated for Flat Panel Display (FPD) glass. A theoretical analysis of the ablation threshold and depth is described using an explicit analytic form. Experiments for clean and deep grooves were performed using a 3W femto-second laser, and the relationships between the input energy and the scribing depth as well as the threshold energy are presented. Mechanical breaking after the scribing process was carried out and the results are compared with a theoretical method. It was found that a two-sided LCD panel glass can be cut clearly using the laser cutting method. The methodology was found to be very effective as a mass-production cutting system.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.24 no.4
• /
• pp.428-433
• /
• 2015

A non-symmetric laser beam was used for cutting a thin glass substrate and its effect was investigated. In laser cutting of brittle materials, controlling crack initiation on the surface is crucial; however, it is difficult to ensure that crack propagation occurs according to a designed laser path. A lot of deviation in crack propagation, especially at the edge of the substrate, is usually observed. A non-symmetric laser beam generates a non-uniform energy distribution, which enhances directional crack propagation. A 20-W pulsed YAG laser was used for cutting a thin glass substrate. Parametric analysis was carried out and the crack control of the non-symmetric laser beam was improved. A theoretical model was presented and the limitations of the proposed process were also discussed.

• Laser Solutions
• /
• v.18 no.3
• /
• pp.9-13
• /
• 2015

The development of a reliable, high-power source of mind-IR laser light gives process develop important tool with unique characteristics that will significantly impact a diverse range of applications.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.497-498
• /
• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.117-118
• /
• 2009

• Journal of the Korean Society for Precision Engineering
• /
• v.27 no.6
• /
• pp.32-38
• /
• 2010

Laser material processing technology is adopted in several industry as alternative process which could overcome weakness and problems of present adopted process, especially semiconductor and display industry. In semiconductor industry, laser photo lithography is doing at front-end level, and cutting, drilling, and marking technology for both wafer and EMC mold package is adopted. Laser cleaning and de-flashing are new rising technology. There are 3 kinds of main display industry which use laser technology - TFT LCD, AMOLED, Touch screen. Laser glass cutting, laser marking, laser direct patterning, laser annealing, laser repairing, laser frit sealing are major application in display industry.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
• /
• 2005.05a
• /
• pp.219-223
• /
• 2005

Nowadays laser cutting is the most promising method of cutting FPD(Flat Panel Display) glass in mass-production line. And this method can also be used to cut other brittle materials such as quartz, sapphire, ceramic and semiconductor The concept of this method is shown in picture 1. Laser beam heats glass up to strain point, not to melting point and cooling system chills glass to induce maximun thermal stress in glass surface and then the thermal stress generates micro thermal crack, in other words blind depth of crack, along laser beam and cooling line.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2005.11a
• /
• pp.87-95
• /
• 2005

Laser sealing/cutting technique, one of the 4 core technologies to manufacture self-luminous glass tubes (SLGTs) has been developed. Through the analysis of commercial products it is found that Pyrex Is used for SLGTs. A CO2 laser, which is commonly used for glass work was used for the study The factors affecting the sealing/cutting were laser intensity, duration. Irradiation method, and pressure inside the tube. The whole Process is composed of 2 stages. In the first stage. both ends of the tubes are sealed while tritium is insected in the tubes. And the tritium sealed tubes are cut in the desired size in the second stage. Defocused beam was used for seal ing and focused beam was used for cutting. After the sealing/cutting, the tubes were heat treated to prevent fracture due to the residual heat stress.