• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.391-392
• /
• 2008

최근 나노 금속의 대량 생산에 대한 기술이 확보됨에 따라, 메탈젯을 이용한 연구가 활발히 진행되고 있다. 메탈젯의 연구 범위는 RFID, PCB, MLCC 전극, 태양전지전극, PDP 전극, EMC용재료 등 그 응용 범위를 넓혀 가고 있다. 이러한 응용 기술 대표적인 배선형성 기술인 PCB 제조에 대한 연구는 40um 이하의 고해상도 기판 개발을 요구하고 있다. 선폭은 40um 이하를 유지하면서, 두께는 10um 이상으로 CCL을 대체 하기 위한 기판 형성 기술은 응용기술은 가장 어려운 난이도의 기술이다. 메탈젯 기술은 매우 복합적인 연구분야로 나노 재료의 개발, 인쇄공정의 개발, 기재 표면처리 기술, 헤드 기술의 개발을 동시에 만족할 때 가능하다. 배선 형성을 위하여 나노 잉크를 이용하여 직접 인쇄를 진행하고, 소결하여 전도성을 얻게 된다. 본 연구에서는 미세노즐에 토출 가능한 잉크젯용 잉크 조성을 결정하고, 기판과의 신뢰성을 확보하기 위하여 접착력의 평가, 전도도의 평가, 건조 시간 조절을 통한 Crack 문제 해결, 미세 선폭의 균일성 조절에 관한 실험을 진행하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.42 no.9
• /
• pp.789-794
• /
• 2014

The FPGA is used to the high speed digital satellite communication on the Digital Signal Process Unit of the next generation GEO communication satellite. The high capacity FPGA has the high power dissipation and it is difficult to satisfy the derating requirement of temperature. This matter is the major factor to degrade the equipment life and reliability. The thermal control at the equipment level has been worked through thermal conduction in the space environment. The FPGA of CCGA or BGA package type was mounted on printed circuit board, but the PCB has low efficient to the thermal control. For the FPGA heat dissipation, the heat sink was applied between part lid and housing of equipment and the performance of heat sink was confirmed via thermal vacuum test under the condition of space qualification level. The FPGA of high power dissipation has been difficult to apply for space application, but FPGA with heat sink could be used to space application with the derating temperature margin.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.338-339
• /
• 2008

현재 PCB (Printed circuit board) 산업은 디스플레이, 모바일 시장의 수요 증가로 인해 활성화 되면서 다앙한 분야로 확대 되어가고 있다. 전자기기의 직접화, 고속파, 사용 주파수 영역의 증가로 인해 수십 GHz 영역에서도 활용이 가능한 소재 및 기판의 필요성이 대두되어 지고 있어 이에 대응할 수 있는 소재 개발도 다양해지고 있다. 본 논문에서는 GHz 영역에서 인쇄회로기판의 회로형태가 특성에 미치는 영향에 대해 연구하였다. 이를위해 패턴도금법과 에칭법으로 회로를 형성하였다. 패턴도금법으로 형성된 시편은 무전해 구리도금 공정을 거친 후 감광성 필름을 이용하여 전해 도금방법을 패턴을 형성하여 회로를 구현하였고, 에칭 패턴 시편은 FR4를 이용하여 동박접합과 도금 공정 후 마스크 패턴을 사용하여 노광, 현상, 에칭 공정을 거쳐 회로를 구성하였다. GHz영역에서 Transmission Line 특성을 분석하였으며 구리 패턴과 절연체사이의 계면형태가 특성에 영향을 주는 것을 확인할 수 있었다.

• Journal of KIISE:Computer Systems and Theory
• /
• v.32 no.3
• /
• pp.133-147
• /
• 2005

Various types of ray-tracing methods are used to predict the quantity measures of radiation illumination, the uniformity of illumination, radiation performance of LCD BLU(Hack-Light Unit). The uniformity of radiation illumination is one of the most important design factor of BLU and is usually controlled by the diffusive-ink pattern printed on the bottom of light-guide panel of BLU. Therefore it is desirable to produce an improved (ideally, the optimal) ink pattern to achieve the best uniformity of radiation illumination. In this paper, we applied the Welder-Mead simplex-search method among various direct search method to compute the optimal ink pattern. Direct search methods are widely used to optimize the functions which are often highly nonlinear, unpredictably discontinuous, and nondifferentiable, The ink-pattern controlling the uniformity of radiation illumination is one type of these functions. In this paper, we found that simplex search methods are well suited to computing the optimal diffusive-ink pattern. In extensive numerical testing, we have found the simplex search method to be reasonably efficient and reliable at computing the optimal diffusive-ink pattern. The result also suggests that optimization can improve the functionality of simulation tools which are used to design LCD BLU.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.12 no.2
• /
• pp.13-29
• /
• 2001

The study examined the current status and the use of electronic publishing files to produce a bibliographic database. In particular . it examined the problems faced in the production of KoreaMed, an abstract database of Korean medical journals. The methodology of KoreaMed to utilize the computer files which was produced in the process of publication of a print journal is found to be very effective. It assures the accuracy of data, accelerates the input speeds, and reduces the input costs. However, such a project can not be accomplished to a satisfactory level without the cooperation of the publishers involved. It turns out that many small publishers and academic societies hardly have saved the electronic publishing files of previous issues. Besides, it is hard to maintain the right channel to receive the files continuously. The input and processing of special characters are very delicate problems. In addition, the diversity of layout and formats of journals, of the electronic publishing software used, and of the storage media, makes the utilization of the electronic publishing files a very complex process. In order to operate the KoreaMed system more efficiently by requiring the publishers to submit XML files which meets the standard of the KoreaMed, it is necessary to educate and train personnels of journal publishers for the management of electronic publishing files.

• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.11
• /
• pp.191-198
• /
• 2000

Laser direct patterning of the coated photoresist (PMER-NSG31B) layer was studied to make halftone dots on gravure printing roll. The selective laser hardening of photoresist by Ar-ion laser(wavelength: 333.6~363.8nm) was controlled by the A/O modulator. The coating thickness in the range of 5~11$\mu m$ could be obtained by using the up-down directional moving device along the vertically located roll. The width, thickness and hardness of the hardened lines formed under the laser power of 200~260㎽ and irradiation time of 4.4~6.6 $\mu$sec/point were investigated after developing. The hardened width increased as the coating thickness increased. Though the hardened thickness was changed due to the effect of the developing solution, the hardened layer showed good resistance to the scratching of 2H pencil. Also, the hardened minimum line widths of 10$\mu m$ could be obtained. The change of line width was also found after etching, and the minimum line widths of 6$\mu m$ could be obtained. The hardened lines showed the good resistance to the etching solution. Finally, the experimental data could be applied to make gravure halftone dots using the developed imaging process, successfully.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.19 no.11
• /
• pp.2276-2290
• /
• 1994

In this paper, we propose an algorithm for character recognition using the subdivided type and the stable structure information. The subdivided type of character is acquired from the stable structure information of character which is extracted from an input character. Firstly, the character is obtained from a scanner and classified into on of 6 types by using directional density vector. And then, the stable structure information is extracted from each character and the character is subdivided into on of 26 types. Finally, the classified character is recognized by using neural network which is inputted the directional density vector equivalent to JASO area or recognized direct. Aa a result of experiment with KS C 5601 2350 printed Hangeul characters, we obtain the recognition rate of 94%.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.6
• /
• pp.550-557
• /
• 2003

In this paper, two dualband internal antennas for GPS/PCS handset are proposed. At first, the monopole antenna with parasitic dipole element is designed to print PCB of handset directly. At second, the antenna with bended loop structure is designed to bend to use internal space of handset maximumly. The proposed dualband internal antennas provide a 2:1 VSWR bandwidth of over 19.1 % which are possible to cover two bands at once. the antennas have a gain between -0.4 and 3.33 ㏈i at all bands and they have almost omni-directional patterns.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.9
• /
• pp.1918-1924
• /
• 2011

This article proposes a POD system framework which creates templates by using the Web service environment with good accessibility, provides them so that users can easily edit them, and uses COM ports following Web standard capable of real-time printing with the same quality as edited files. The characteristic of framework proposed in this article is that it creates programs which users with basic skill in Internet use can learn and use relatively easily when compared with existing specialized editing programs and which allows users to print real-time such files as personally created by them in the same quality as on the screen, and thereby enhances accessibility thereof.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.16 no.2
• /
• pp.291-297
• /
• 1998

In order to accomplish the digital map production I/O devices should be used which are used for data input procedure to convert original paper map(hardcopy) data into computer compatible digital map data, and for the mapsheet output procedure of worked out data. For the input device, digitizer and scanner are most frequently used. Digitizer has possibility of direct production of digital data, and are mainly used for input procedure of partly plotted source map. In contrary, scanner is rather easy to operate the instrument, so that is widely used for the input procedure of original sheet map. In this study, to extract the input device characteristics, some kinds of digitizers and scanners were cheesed and used for the positional error analysis through the operational method and types of instruments. Also for the output device characteristics, some kinds of plotter and materials are used and compared to analyze the positional error through the instrumental types and output sheet materials.