• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.8 no.1
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• pp.30-35
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• 2009

In this paper, the type of inkjet heads and the control of head of inkjet printer are surveyed. The electronic parts of inkjet printer are composed of main- board and sub-board. The inkjet head is controlled by using these boards. The results from silver ink jetting experiment are given. The results show that the implemented inkjet system can give a satisfactory performance.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.1
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• pp.57-65
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• 2016

This paper was analyzed the characteristics of piezoelectric inkjet print head using finite element method(FEM). It showed the bending node driving of piezoelectric and relation theory principle consider piezoelectric material characteristics and ink characteristics. From such result we were had the piezoelectric head design and manufacture. It got a this head characteristics through experiment, we confirmed that proper voltage control is possible to through ink drop control experiment of piezoelectric print head. This paper was obtained the suitable ink jetting characteristics that manufacture the control circuit and piezoelectric inkjet print head. This practice product was applied to improvement of PCB electric circuit pattern by etching resist ink that PCB manufactured to complex process over traditional 6 stages can be simpled to 1 stage by inkjet printing technology.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.4
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• pp.141-145
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• 2009

Recently, inkjet technology has emerged as one of the most powerful tools for patterning electronics devices, such as large area display applications, RFID, PCB patterning, etc. By using the Inkjet technology, the droplet speed as well as the size can be controlled precisely. In this paper, the relationship between waveform and droplet size will be investigated by means of experiment. Also the relationship between inkjet speed and droplet size will be discussed. It was shown from experimental results that ink droplet size from the nozzle diameter of $50{\mu}m$ can be varied from 37 to $58{\mu}m$ by modifying the inkjet waveform when the speed of the droplet is 1m/sec. Finally, experimental results indicate that small drops are more difficult to generate than large drops since the jetting conditions for making small drops are sensitively affected by the dwell time variation.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.5
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• pp.89-96
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• 2007

Inkjet printing has become one of the most attractive manufacturing techniques in industry. Especially inkjet printing technology will soon be part of the PCB (Printed Circuit Board) fabrication processes. Traditional printing on PCB includes screen printing and photolithography. These technologies involve high costs, time-consuming procedures and several process steps. However, by inkjet technology manufacturing time and production costs can be reduced, and procedures can be more efficient. PCB manufacturers therefore willingly accept this inkjet technology to the PCB industry, and are quickly shifting from conventional to inkjet printing. To produce the printed circuit board by the inkjet technology, it must be harmonized with conductive nano ink, printing process, system, and inkjet printhead. In this study, micro patterning of conductive line has been investigated using the piezoelectric printhead driven by a bipolar voltage signal is used to dispense 20-40 ${\mu}m$ diameter droplets and silver nano ink which consists of 1 to 50 nm silver particles that are homogeneously suspended in an organic carrier. To fabricate a conductive line used in PCB with high precision, a printed line width was calculated and compared with printing results.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.446-450
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• 2007

It is strongly expected that inkjet printing method will be play and important role on printable electronics such as 3D integration of embedded ceramic devices(capacitor, resistor, inductor and electrode or circuit), Si-TFT and organic TFT including display C/F, RFID, FPCB, and etc. A inkjet printing method had been center of attention to strengthen the competitiveness of flat panel display on market and to open the new world of manufacturing process of printable electronics. We will survey the industrial tendency of printable electronics and flat panel display including some examples of inkjet printing and present the considerable points of inkjet printing method and some role of materials for successful inkjet printing.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1476-1478
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• 2009

The characteristics of polymer inkjet printing were investigated systematically in this paper. PEDOT/PSS as a hole injection layer and MEH-PPV as a light emitting layer were used for inkjet printing experiment. Inkjet head controlling technology and surface modification technology were also applied for polymer inkjet printing. With the developed polymer inkjet printing technology, OLED(Organic Light Emitting Display) was successfully fabricated and demonstrated.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.8
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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.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.913-918
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• 2005

It is expected that the inkjet technology offers prospect for reliable and low cost manufacturing of FPD (Flat Panel Display). This inkjet technology also offers a more simplified manufacturing process for various part of the FPD than conventional process. For example, recently the novel manufacturing processes of color filter (C/F) in LCD, or RGB patterning in OLED by inkjet printing method have been developed. This elaborates will be considered as the precious point of manufacturing process for the mass production of enlarged-display panel with a low price. On this point of view, we would like to review the status of inkjet technology in FPD, with some results on forming micro line by inkjet patterning of suspension type silver nano ink as below. We have studied the inkjet patterning of synthesized aqueous silver nano-sol on interface-controlled ITO glass substrate. Furthermore, we designed the conductive ink for direct inkjet patterning on bare ITO glass substrate. The first, the highly concentrated polymeric dispersant-assisted silver nano sol was prepared. The high concentration of batch-synthesized silver nano sol was possible to 40 wt%. At the same time the particle size of silver nanoparticles was below $10{\sim}20nm$. The second, the synthesized silver nano sol was inkjet - patterned on ITO glass substrate. The connectivity and width of fine line depended largely on the wettability of silver nano sol on ITO glass substrate, which was controlled by surfactant. The relationship was understood by wetting angle. The line of silver electrode as fine as $50{\sim}100\;{\mu}m$ was successfully formed on ITO glass substrate. The last, the direct inkjet-patternable silver nano sol on bare ITO glass substrate was designed also.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2563-2566
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• 2007

TFT LCD industries have endeavored to adopt the piezo Drop-On-Demand (DOD) inkjet printing technology to production lines of TFT LCD color filters and these efforts have significantly been based on experimental works. Because the degree of complexity in the piezo DOD inkjet printing technology results in too many combination of parameters, the matrix experimental method to investigate all possible sets of parameters becomes ineffective and hence the basic understanding of the piezo Drop-On-Demand inkjet print technology becomes important. In this study, one possible cause of the droplet volume variation across nozzles, which might cause visible swathe marks on an inkjet patterned TFT LCD color filter, is theoretically investiaged and new R&D directions are suggested.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1444-1449
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• 2007

Inkjet printing technology with a drop-on-demand (DOD) inkjet head technology has been recognized as one of versatile and low cost manufacturing tools in the electronics industry. Concerned with control of driving signal, however, general strategy to optimize jetting stability has not been understood well, because of the inherent complex multi-physics nature in inkjet phenomena. Motivated by this, present study investigates the effect of driving waveforms of piezoelectric head on jetting characteristics of DOD inkjet system focused on jetting stability with phase matching of pressure waves in the print head. The results show that velocities and volumes of the ink jetted droplets were linear relations with the driving signal's maximum voltage, while periodic behaviors are observed with the driving signal's pulse widths.