• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.451-454
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• 2007

This paper presents the pattern characteristic using the electrostatic drop-on-demand ink-jet printing system. In order to achieve the pattern characteristic of electrostatic inkjet printing, the capillary inkjet head system is fabricated using capillary tube, Pt wire and electrode, and is packaged by acrylic board for the accurate alignment between wire and electrode-hole. The applied DC voltage of 1.4 $\sim$ 2.0 kV used for the observation of electrostatic droplet ejection. Electrostatic droplet ejection is directly observed using a high-speed camera. For investigated pattern characteristic, conductive inkjet silver ink used. The higher voltage has a good condition which has micro dripping mode. Also, the droplet size decreases with increasing the supplied DC voltage. This paper shows the pattern which is formed by about 300um. Also, capillary inkjet head system will be applied industrial area comparing conventional electrostatic inkjet head system.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 춘계학술발표대회
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• pp.13.2-13.2
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• 2009

Electrostatic printing either it is drop-on-demand or continuous has immense applications in non-contact printing systems such as solar cells, flexible printed circuits, RFIDs and bio applications. In this paper a laboratory manufactured nozzle has been designed for the experimental investigation of electrostatic dripping and atomization of liquid. Dripping and atomization conditions such as voltage, nozzle tip diameter, distance between counter electrode and flowrate has been indentified for the designed nozzle. Furthermore it is also demonstrated that the diameter of a generated droplet could be reduced from a significantly large size to a narrow size distribution which can be controlled by volumetric flow rate and applied voltage. This study will help in classify the conditions between different electrostatic dripping mode such as drop-on-demand formation, jet mode and finally the atomization mode based on the laboratory fabricated nozzle head.

• 전기학회논문지
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• 제56권8호
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• pp.1445-1449
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• 2007

This paper presents the DOD (Drop-On-Demand) characteristic using the electrostatic field induced inkjet printing system. In order to achieve the DOD characteristic of electrostatic field induced inkjet printing, applied the bias voltage of 1.4 kV and the pulse voltage of $2.0\;kV\;{\sim}\;2.7\;kV$ using high voltage pulse generator. Electrostatic field induced droplet ejection is directly observed using a high-speed camera and for investigated DOD characteristic, CNT ink used. The electrostatic field induced inkjet head system has DOD characteristic using pulse generator which can be applied pulse voltage. The bias voltage has a good condition which form meniscus and has micro dripping mode for small size micro droplet. Also, the droplet size decreases with increasing the applied pulse voltage. This paper shows DOD characteristic at electrostatic field induced inkjet head system, Therefore. electrostatic DOD inkjet head system will be applied industrial area comparing conventional electrostatic inkjet head system.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1947-1950
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• 2008

Printing technology is a very useful method in the several process of industrial fabrication due to noncontact and fast pattern generation. To make micro pattern, we investigate the electrostatic induced inkjet printer head for micro droplet generation and drop-on-demand jetting. In order to achieve the drop-on-demand micro droplet ejection by the electrostatic induced inkjet printer head, the pulsed DC voltage is supplied. In order to find optimal pulse conditions, we tested jetting performance for various bias and pulse voltages for drop-on-demand ejection. In this result, we have successful drop-on-demand operation and micro patterning. Therefore, our novel electrostatic induced inkjet head printing system will be applied industrial area comparing conventional printing technology.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.665-666
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• 2011

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.505-508
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• 2006

An electrostatic ink jet head can be used for manufacturing processes of large display systems and printed circuit boards (PCB) as well as inkjet printers because an electrostatic field provides an external force which can be manipulated to control sizes of droplets. The existing printing methods such as thermal bubble and piezo inkjet heads have shown difficulties to control the ejection of the droplets for printing applications. Thus, the new inkjet head using the electrostatic force has been proposed in this study. In order to prove the theory of the developed electrostatic ink jet head, the applicable and basic theory has been studied using distilled water and water with sodium dodecyl surfate (SDS). Also, a numerical analysis has been performed to calculate the intensity of the electrostatic field using the Maxwell's equation. Furthermore, experiments have been carried out using a downward glass capillary with outside diameter of $500{\mu}m$. The gravity, surface tension, and electrostatic force have been analyzed with high voltages of 0 to 5kV. It has been observed that the droplet size decreases and the frequency of the droplet formation and the velocity of the droplet ejection increase with increasing the intensity of the electrostatic field. The results of the experiments have shown good agreement with those of numerical analysis.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2007년도 추계학술대회
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• pp.128-133
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• 2007

An electrostatic inkjet head can be used for manufacturing processes of large display systems and printed circuit boards (PCB) as well as inkjet printers because an electrostatic field provides an external force which can be manipulated to control sizes of droplets. The existing printing methods such as thermal bubble and piezo inkjet heads have shown difficulties to control the ejection of the droplets for printing applications. Thus, the new inkjet head has been proposed using the electrostatic force. A numerical analysis has been performed to calculate the intensity of the electrostatic field using the Maxwell's equation. Also, experiments have been carried out to investigate the droplet movement using a downward capillary with outside diameter of $500{\mu}m$. Gravity, surface tension, and electrostatic force have been analyzed with high voltages for a drop-on-demand ejection. It has been observed that the droplet size decreases and the frequency of the droplet formation and the velocity of the droplet ejection increase with increasing the intensity of the electrostatic field using high-speed camera.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.715-716
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• 2008

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1103-1106
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• 2008

For the current display process, the innovative micro pattern fabrication process using semiconductor process should be developed, which requires the expensive equipment, the limited process environment and the expensive optic-sensitive material. The effort of process innovation during past several years ends up the limit of cost reduction. The existing ink jet technologies such as a thermal bubble ink jet printing and a piezo ink jet printing are required to shorten the nozzle diameter in order to apply to the micro pattern fabrication. In this paper, as one way to cope these problems the micro pattern equipment based on the electrostatic ink jet has been developed and carried out some experiments.

• 소성∙가공
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• 제24권2호
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• pp.83-88
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• 2015

For chromaticity correction, it is necessary to dispense high viscosity phosphor slurry since it greatly affects the performance of white LEDs. However, it is quite difficult to dispense high viscosity fluorescent materials. In the current study, micro-discharge electrostatic printing has been used for dispensing various high viscosity phosphor slurries. We have achieved dispersions of up to 50 µg using drop on demand (DOD) discharge experiments. The experiments were conducted with different combinations of process variables such as applied voltage, pneumatic pressure, and frequency.