• 정보저장시스템학회논문집
• /
• 제1권1호
• /
• pp.108-114
• /
• 2005

The generation of fine relics of suspensions is a significant interest as it holds the key to the fabrication of electronic devices. These processes offer opportunities for miniaturization of multilayer circuits, for production of functionally graded materials, ordered composites and far small complex-shaped components. Some novel printing methods of depositing ceramic and metal droplets were suggested in recent years. In an electro-hydrodynamic printing, the metallic capillary nozzle can be raised to several kilovolts with respect to the infinite ground plate or pin-type electrode positioned a few millimeters from the nozzle tip. Depending on the electrical and physical properties of the liquid, for a given geometry, it Is possible to generate droplets in any one of three modes, dripping, cone-jet and multi-jet. In this experiment, an alumina suspension flowing through a nozzle was subjected to electro-hydrodynamic printing using pin-type electrodes in the cone-jet mode at different applied voltages. The pin-type electrodes of 1, 100, 1000${\mu}m$ in diameter were used to form fine ceramic patterns onto the substrates. Various feature sizes with applied voltages and electrode diameters were measured. The feature sizes increased with the electrode diameter and applied voltages. The feature size was as fine as $30 {\mu}m$.

• 한국정밀공학회지
• /
• 제29권3호
• /
• pp.295-301
• /
• 2012

The method for spraying of liquids through an electrical field has become a printing method since it can make very small droplet. For electro-hydrodynamic jet printing to become a reliable jetting tool, the jetting performance should be characterized with respect to various jetting conditions. To optimize jetting conditions, the jetting behavior should be measured. In this study, we present a visualization techniques to measure jetting behavior from electro-hydrodynamic (EHD) inkjet head. Unlike most previous method, we use the CCD camera to measure the jetting behavior. For this purpose, LED light is synchronized with jetting signal and sequential image was obtained by adjusting the delay time of the LED light. Finally, merits and demerits of using CCD camera were discussed to measure jetting image from EHD inkjet head.

• 대한기계학회논문집B
• /
• 제29권4호
• /
• pp.504-511
• /
• 2005

The generation of fine relics of inorganic and metallic materials from precursor suspensions is of significant current interest as it holds the key to the fabrication of display and printed circuit board. Some novel printing methods depositing ceramic particles have been suggested in recent years. When a conducting liquid is supplied to a capillary nozzle at a low flow rate and when the interface between air and the liquid is charged to a sufficiently high electrical potential, the liquid meniscus takes the form of a stable cone, whose apex emits a microscopic jet. This is called as a cone-jet mode. In our experiments, an alumina particles flowing through a nozzle were subjected to electro-hydrodynamic printing in the cone-jet mode. The pattern of 'YONSEI' characters was tested at $10 {\mu}l/min$ of alumina ink flow rate and different applied voltages. At an applied voltage of 6 kV, feature size was in the range of $250 {\mu}m.$

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2012년도 춘계학술대회 논문집
• /
• pp.113-114
• /
• 2012

• 한국정밀공학회지
• /
• 제29권4호
• /
• pp.449-454
• /
• 2012

The method for spraying of liquid through an electrical filed has become a printing method since it can make very small droplet. To increase the reliability using the electro-hydrodynamic (EHD) jet printing, the jetting status needs to be monitored. Vision measurement techniques using high speed camera has been used to visualize the jet images. However, it requires image processing of a lot of images after image acquisitions. So, it is difficult to understand jet behavior such as jetting frequency, jet repeatability etc. In this work, a low cost electrical current measurement method was developed to measure electrical current from EHD jet printing. To verify the jetting monitoring capability of developed circuit, images from high speed camera were processed for comparison purpose.