• Korean Journal of Materials Research
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• v.20 no.11
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• pp.617-622
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• 2010

We have studied methods to save Si source during the fabrication process of crystalline Si solar cells. One way is to use a thin silicon wafer substrate. As the thickness of the wafers is reduced, mechanical fractures of the substrate increase with the mechanical handling of the thin wafers. It is expected that the mechanical fractures lead to a dropping of yield in the solar cell process. In this study, the mechanical properties of 220-micrometer-solar grade Cz p-type monocrystalline Si wafers were investigated by varying saw-damage etching conditions in order to improve the flexural strength of ultra-thin monocrystalline Si solar cells. Potassium hydroxide (KOH) solution and tetramethyl ammonium hydroxide (TMAH) solution were used as etching solutions. Etching processes were operated with a varying of the ratio of KOH and TMAH solutions in different temperature conditions. After saw-damage etching, wafers were cleaned with a modified RCA cleaning method for ten minutes. Each sample was divided into 42 pieces using an automatic dicing saw machine. The surface morphologies were investigated by scanning electron microscopy and 3D optical microscopy. The thickness distribution was measured by micrometer. The strength distribution was measured with a 4-point-bending tester. As a result, TMAH solution at $90^{\circ}C$ showed the best performance for flexural strength.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.20-23
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• 2001

Plasma Display Panel(PDP) is a type of flat panel display utilizing the light emission produced by gas discharge. Barrier Ribs of PDP separating each sub-pixel prevents optical and electrical crosstalks from adjacent sub-pixels. The mold for forming the barrier ribs has been newly researched to overcome the disadvantages of conventional manufacturing processes such as screen printing, sand-blasting and photosensitive glass methods. The mold for PDP barrier ribs have stripes of micro grooves transferring glass-material wall. In this paper, Stripes of grooves of which width 48${\mu}{\textrm}{m}$, depth 124$\mu\textrm{m}$ , pitch 274$\mu\textrm{m}$ was acquired by machining of single crystal silicon with dicing saw blade. Maximum roughness of the bottom of the grooves was 59.6nm Ra in grooving Si. Barrier ribs were formed with silicone rubber mold, which is transferred from grooved Si forming hard mold. Silicone rubber mold has the elasticity, which enable to accommodate the waveness of lower glass plate of PDP. The methods assisted by the microwave and UV was adopted for reducing the forming time of glass paste.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1623-1624
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• 2006

It is a paper for design, manufacture and estimation of industry inkjet head. Simulations for Actuator, Ink flow and Ejection are executed for securing design ability. Relations between droplet and properties of ink are explained closely through simulation for nozzle. Actually, two silicon plates are made by dry and wet etching and directly bonded. PZT materials is attached on the bended ink flow part and cut to $540{\mu}m$ interval by dicing saw. Actuator was seen variation within 10% between simulation and actual head. Through the ejection estimation, it is shown that stabilized driving voltages change according to viscosity and surface tension of metal ink. Using the metal ink of viscosity of 4.8 cps and surface tension of 0.025 N/m, it is possible to eject the stable droplets with 5m/s, 20 pl, 5 kHz.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.6
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• pp.176-183
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• 2002

Plasma Display Panel(PDP) is a type of flat panel display utilizing the light emission produced by gas discharge. Barrier Ribs of PDP separating each sub-pixel prevents optical and electrical crosstalks from adjacent sub-pixels. The mold for forming the barrier ribs has been newly researched to overcome the disadvantages of conventional manufacturing processes such as screen printing, sand-blasting and photosensitive glass methods. The mold for PDP barrier ribs have stripes of micro grooves transferring glass-material wall. In this paper , Stripes of grooves of which width 48$\mu$m, depth 124$\mu$m , pitch 274$\mu$m was acquired by machining of single crystal silicon with dicing saw blade. Maximum roughness of the bottom of the grooves was 59.6 nm Ra in grooving Si. Barrier ribs were farmed with silicone rubber mold, which is transferred from grooved Si forming hard mold. Silicone rubber mold has the elasticity, which enable to accommodate the waviness of lower glass plate of PDP. The methods assisted by the microwave and UV was adopted for reducing the forming time of glass paste.