• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1340_1341
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• 2009

In this report, high-resolution metal electrode patterning is demonstrated by using selective surface treatment and dip casting for low-cost printed electronic applications. On hydrophobic octadecyltrichlorosilane treated $SiO_2$ surface, deep UV irradiation was performed through a patterned quartz photomask to selectively control the surface energy of the $SiO_2$ layer. The deep UV irradiated region becomes hydrophilic and by dipping into Ag nano-ink, Ag patterns were formed on the surface. Using this patterning technique, line patterns and dot arrays having less than $10{\mu}m$ pitch were fabricated.

• 한국세라믹학회지
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• 제48권6호
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• pp.543-548
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• 2011

The inkjet printing technology has undergone remarkable development since the concept of printed electronics was first introduced. The large interest which it has sparkled is due to its many enticing features such as processing simplicity, low cost and scalability as well as its compatibility with flexible electronics. Thanks to constant improvements, inkjet printing has nowadays become a mature technology which is an effective replacement for a number of intricate and expensive conventional laboratory tools and is also on the verge of gaining industrial significance. Technological challenges which still remain open include low temperature processing, high density integration and reproducibility. This paper reviews some recent advances in the inkjet printing technology, addressing those issues. And we also discuss a number of novel approaches to performing inkjet printing.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.551-552
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• 2006

This study was attended to demonstrate synthesis of silver nanoparticles stabilized with polymer and their applicability to printed electronics. Silver nanoparticles were synthesized by reduction of silver nitrate in aqueous solution in the presence of polyvinyl pyrrolidone (PVP) as a stabilizer. The ink used here is composed of 50 wt% Ag NP, 15 wt% humectant and then were printed on polyimide film. Particle deposit morphologies were controlled by varying the ink compositions. Printed silver patterns and dots were cured on a convection oven in air at $300^{\circ}C$ for 60 min. The printed patterns show good shape definition and the resistivity of the printed films is about $5{\mu}{\Omega}{\cdot}cm$.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.739-740
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• 2012

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.465-466
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• 2011

• 전자공학회논문지B
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• 제32B권10호
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• pp.1347-1357
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• 1995

In this paper, we describe a modularized neuroclassifier for enhancing the recognition accuracy of mixed printed and handwritten numerals. This classifier combines four modularized subclassifiers using multi-layer perceptron module. The input of each subclassifier is comprised of a group of specialized feature sets. On applying this method to combining several subclassifiers for unconstrained handwritten numerals, the experimental result shows that the performance of individual subclassifier can be improved. In winner-take-all voting method, the result of subclassifier having the highest RF value is selected as the output. The generality of this classifier is tested with 1,080 printed and 3,000 handwritten numerals that was not shown in training the neural networks. Experimental results show 98.2% recognition rate. The typical recognition test with a threshold value(RF=1.5) has shown 97% recognition, 1% substitution and 2% rejection rates.

• 한국분말재료학회지
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• 제19권5호
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• pp.343-347
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• 2012

In this study, an oxygen plasma treatment was used as a low temperature debinding method to form a conductive copper feature on a flexible substrate using a direct printing process. To demonstrate this concept, conductive copper patterns were formed on polyimide films using a copper nanoparticle-based paste with polymeric binders and dispersing agents and a screen printing method. Thermal and oxygen plasma treatments were utilized to remove the polymeric vehicle before a sintering of copper nanoparticles. The effect of the debinding methods on the phase, microstructure and electrical conductivity of the screen-printed patterns was systematically investigated by FE-SEM, TGA, XRD and four-point probe analysis. The patterns formed using oxygen plasma debinding showed the well-developed microstructure and the superior electrical conductivity compared with those of using thermal debinding.

• 한국정밀공학회지
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• 제32권9호
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• pp.833-840
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• 2015

Inkjet technology is one of the commonly used technologies in the printed-electronics field. The primary issue regarding the usage of inkjet technology as a printed-electronics tool is the printing resolution; therefore, to print complicated patterns of precise dimensions, we developed software that can convert a CAD file into a bitmap image. Moreover, as a bitmap image is not comprised of physical dimensions, its resolution needs to be defined in terms of pixel distance to print a rasterized bitmap image. In this study, we investigated the effects of pixel distance and dot size on printing resolution; based on the experiment results, we concluded that the printed dot size should be used to determine the optimal pixel distance. Lastly, we also propose inkjet printing procedures for bitmap images.

• 전자공학회지
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• 제38권4호
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• pp.24-30
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• 2011

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.4.1-4.1
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• 2011

Recently, circuit printing technology has been considered as a promising alternative to conventional PCB fabrication, for it can greatly reduce the manufacturing costs. Even though printed circuit has many advantages over typical subtractive technology such as fewer processes, it has some disadvantages. The major problems are low adhesion and poor resolution. Efforts to overcome these problems have been mainly focused on ink developments with a limited success. And surface treatments showed some improvements. Therefore, various plasma treatments and primer coatings on plastic substrates have been tested. Plasma treatments using hydrocarbon gases including methane and propane improved the pattern quality of the inkjet printed circuit, which are further improved upon heating of substrate. On the other hand, there is little effect on the adhesion, which is improved only by a special primer coating. The adhesion of inkjet printed circuit has been increased more than 10 times upon treatment. As for the screen printed circuits, the overall effects are less significant since there is some organic binder in the ink. Nonetheless, the treatment has strong positive effects on pattern quality and adhesion. The adhesion of 1 kgf/cm2, which is comparable with those of the conventional PCB circuits, is possible through primer coating for both screen and inkjet printed circuits. The resulting circuit also showed good thermal, mechanical and electrical properties.