• Laser Solutions
• /
• v.16 no.4
• /
• pp.12-16
• /
• 2013

For mass production of electronic devices, the processing of the printing roll is one of the most important key technologies for printed electronics technology. A roll of printing process, the gravure printing that is used to print the electronic device is most often used. The indirect laser processing has been used in order to produce printing roll for gravure printing. It consists of the following processing that is coating of photo polymer or black lacquer on the surface of printing roll, pattering using a laser beam and etching process. In this study, we have carried out study on the coating and etching for $25{\mu}m$ line width on the printing roll. To do this goals, a $4{\mu}m$ coating thickness and 20% average coating thickness of the coating homogeneity of variance is performed. The factors to determine the thickness and homogeneity are a viscosity of coating solution, the liquid injection, the number of injection, feed rate, rotational speed, and the like. After the laser patterning, a line width of $25{\mu}m$ or less was confirmed to be processed through etching and the chromium plating process.

• Laser Solutions
• /
• v.17 no.4
• /
• pp.20-23
• /
• 2014

In printed electronics, printing rolls are used to transfer electronic ink onto a flexible substrate. Generally printing rolls are patterned in microscale by the indirect laser method. Since based on the wet etch process, the indirect method is neither environment-friendly nor suitable for making a printing roll with patterns narrower than $20{\mu}m$. In this paper, we have directly engraved micro-patterns into a Zn-coated metal specimens using a picosecond laser in order both to engrave $10{\mu}m$-wide patterns and to improve the pattern profile. Experiments showed that it is possible to engrave $10{\mu}m$-wide patterns with an a rectangular-shaped profile which is necessary for the dimensionally accurate printing.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1395-1396
• /
• 2008

본 논문에서는 초소형 DC-DC 컨버터에 쓰이는 파워인덕터를 설계하였다. 제안된 인덕터는 Ni-Zn 페라이트와 Polyimide 혼합물질을 이용하여, 경화온도를 낮추어 유기기판(FR-4)에서도 적용될 수 있는 인덕터를 설계했다. 인덕터의 크기는 $5mm{\times}4.5mm{\times}0.5mm$ 이고, 도선의 물질은 구리(Cu)를 사용하였으며, 18${\mu}m$의 두께, 85${\mu}m$의 선폭, 85${\mu}m$의 선 간격으로 디자인 하였다. 그리고 구조는 2층 적층의 스파이럴 구조를 제안하여 소형화에 보다 유리하도록 설계를 하였다. 페라이트 혼합물질을 샌드위치 타입으로 EMI shielding한 인덕터의 경우 동작 주파수 5MHz에서 912nH의 인덕턴스, 29의 품질계수 특성을 나타냈으며, 그 결과 초소형 DC-DC 컨버터용 인덕터로서 소형화와 높은 효율을 만족하였다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.42 no.4
• /
• pp.716-722
• /
• 2017

In this paper, a fully printed NFC tag operating at 13.56 MHz was designed and fabricated using silver nano-paste and carbon ink. The proposed NFC tag has a printed coil with an inductance of $2.74{\mu}H$ on a PI film for application to an NFC tag IC with an internal capacitance of 50 pF. Screen printing technology used in this paper has advantages such as large area printing for mass production, low cost and eco-friendly process compared to conventional PCB manufacturing process. The proposed structure consists of a circular coil implemented as a single layer using silver nano-paste and carbon ink, a jumper pattern for chip mounting between the outer edge and the center of the coil, and an insulation pattern between the coil and the jumper pattern. In order to verify the performance of the proposed NFC tag, we performed the measurements of the printing line width, thickness, line resistance, adhesion and environmental reliability, and confirmed the suitability of the NFC tag based on the full-printed manufacturing method.

• Journal of the Korean Ceramic Society
• /
• v.41 no.4
• /
• pp.313-322
• /
• 2004

Thick film photolithography is a new technology in that the lithography process such as exposure and development is applied to the conventional thick film process including screen-printing. In this research, low-temperature cofireable silver paste, which enabled the formation of thick film fine-line using photolithographic technology, was developed. The optimum composition for fine-line forming was studied by adjusting the amounts of silver powder, polymer and monomer, and the additional amount of photoinitiator, and then the effect of processing parameter such as exposing dose on the formation of fine-line was also tested. As the result, it was found that the ratio of polymer to monomer, silver powder loading, and the amount of photoinitiator were the main factors affecting the resolution of fine-line. The developed photosensitive silver paste was printed on low-temperature cofireable green sheet, then dried, exposed, developed in aqueous process, laminated, and fired. Results showed that the thick film fine-line under 20$\mu\textrm{m}$ width could be obtained after cofiring.

• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.6
• /
• pp.477-481
• /
• 2014

Flexible electronics have been to the fore because it is believed that flexibility can add incredible value such as light weight and mobility into the existing electronic devices and create new markets of large-area and low-cost electronics such as wearable eletronics in near future. Offset printing processes are regarded as major candidates for manufacturing the flexible electronics because they can provide the patterning resolution of micron-size effectively in large-area. In view of mechanics, the most important viewpoint in offset printing is how to achieve the synchronized movement of two contact surfaces in order to prevent slip between two contact surfaces and distortion of the blanket surface during ink transfer so that the high-resolution and good-overlay patterns can be printed. In this paper, a novel low-cost measurement method of the synchronization error using the motor control output signals is proposed and the compensation method is presented to minimize the synchronization error.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.305-305
• /
• 2008

LTCC는 고주파영역에서 손실이 낮고 적층구조의 모듈제작이 가능하여 고주파용 모듈제작에 응용이 가능하다. 최근 수동소자가 내장된 ASM이나 FEM 등의 모듈은 그 집적도가 높고 기판의 두께가 감소함에 따라 소재의 고강도 특성이 요구되고 있다. 이와 같은 경향에 따라 Anorthite계 결정화 유리로 알려진 300MPa 이상의 고강도를 나타내는 CaO-Al2O3-SiO2계 소재가 선행 연구 과정을 통하여 개발되었다. 본 실험에서는 기 개발된 조성의 고강도 소재를 이용하여 RF부품에 적용하기 위한 테스트 쿠폰을 제작하였다. 고강도 소재를 이용하여 green sheet를 제조하고 수동소자인 R, L, C 등을 기판 내에 내장화 하기위해 LTCC 공정을 이용하여 각 층에 다양한 선폭 및 크기의 패턴을 인쇄한 뒤 적층하여 $900^{\circ}C$에서 소결하였다. 이 과정에서 공정에 대한 적용성이 각 공정별로 평가되었으며 완성된 테스트 쿠폰을 이용하여 소재의 전기적인 특성을 평가하였다.

• Journal of Drive and Control
• /
• v.21 no.1
• /
• pp.8-15
• /
• 2024

This thesis investigates the jetting characteristics of an aerosol jet printing (AJP) process as a function of design and operating conditions. The governing equations of the AJP system are derived for experimentation and analysis. To understand the characteristics of the AJP system, it analyzes the jetting characteristics as a function of the flow rate of the carrier gas and the sheath gas, and the variation of the linewidth with the nozzle exit size based on particle tracking. The thesis focuses on computational fluid dynamics (CFD), which is a computer simulation. The particle tracking results obtained by CFD were analyzed using MATLAB. CFD analytical models can be analyzed in environments with different conditions and consider more specific situations than mathematical computational models. The validity of the CFD analysis is shown by comparing the experimental results with the CFD analysis.

• Journal of Drive and Control
• /
• v.21 no.2
• /
• pp.8-14
• /
• 2024

This paper investigates the jetting characteristics of an aerosol jet printing (AJP) process as a function of design and operating conditions. The governing equations of the AJP system are derived for experimentation and analysis. To understand the characteristics of the AJP system, this thesis analyzes the jetting characteristics as a function of the flow rate of the carrier gas and the sheath gas, and the variation of the linewidth with the nozzle exit size based on particle tracking. This thesis focuses on computational fluid dynamics (CFD), which is a computer simulation. The particle tracking results obtained by CFD were analyzed using MATLAB. CFD analytical models can be analyzed in environments with different conditions and consider more specific situations than mathematical computational models. The validity of the CFD analysis is shown by comparing the experimental results with the CFD analysis.

• Journal of the Korean Ceramic Society
• /
• v.41 no.10 s.269
• /
• pp.788-791
• /
• 2004

We have studied the fabrication of silver micro lines using the silver nano sol on ITO substrate by an ink-jet method. The average particles size of $10wt\%$ silver nano sol synthesized with polyelectrolytes was smaller than 10 nm. The pattern formation of silver nano sol on the substrate closely related with the contact angle of the silver nano sol. The dot shaped of silver nano sol on bare ITO substrate was formed due to the high contact angle of silver nano sol. When ITO substrates was treated with 100 ppm polyethylenimine for silver nano sol patterning, fine silver micro lines of $60{\sim}100{\mu}m$ width was fabricated by ink-jet method.