• Journal of the Microelectronics and Packaging Society
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• v.13 no.2 s.39
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• pp.1-7
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• 2006

In this paper, warpage magnitude and shape of printed-circuit board in case that properties of core and thickness of solder resist are varied are investigated. The cause of warpage is coefficient of thermal expansion differences of stacked materials. Therefore, we need small difference of coefficient of thermal expansion that laminated material, and need to decrease asymmetric of top side and bottom side in structure shape. Also, we can control occurrence of warpage heightening hardness of core in laminated material. Composite material that make core are exploited in connection with the structural bending twisting coupling resulting from directional properties of fiber reinforced composite materials and from ply stacking sequence. If we use such characteristic, we can control warpage with change of material properties. In this paper, warpage of two layer stacked chip scale package is investigated, and evaluate improvement result using an experiment and finite element method tool.

• The Optical Journal
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• s.144
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• pp.41-43
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• 2013

국내 최대 규모의 전자제조장비 종합 전시회 'Electronics Manufacturing Korea 2013 (2013 한국전자제조산업전)'가 오는 4월 3일부터 5일까지 서울 삼성동 코엑스에서 개최된다. 이번 전시회는 인쇄회로기판과 표면실장기술, LED, 인쇄전자, 기능성 필름, 광학 및 레이저기기 등 전자 제조 산업 전반에 걸친 기술들을 한 곳에서 만날 수 있는 기회가 될 것이다.

• The Optical Journal
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• s.139
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• pp.63-66
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• 2012

국내 최대 규모의 전자제조장비 종합 전시회 'Electronics Manufacturing Korea 2012'가 지난 4월 11일부터 13일까지 코엑스 전시장에서 개최됐다. 이 전시회는 인쇄회로기판과 표면실장기술, LED, 인쇄전자, 기능성 필름, 광학 및 레이저기기 등 전자 제조 산업 전반에 걸친 기술들을 한 곳에서 선보이며 국내 주요 전자산업 핵심 분야별 비즈니스 활성화를 위한 장으로 펼쳐졌다.

• Journal of the Microelectronics and Packaging Society
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• v.24 no.3
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• pp.71-76
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• 2017

The electrical behavior and flexibility of the screen printed Ag circuits were investigated with infrared radiation sintering times and sintering temperatures. Electrical resistivity and radio frequency characteristics were evaluated by using the 4 point probe measurement and the network analyzer by using cascade's probe system, respectively. Electrical resistivity and radio frequency characteristics means that the direct current resistance and signal transmission properties of the printed Ag circuit. Flexibility of the screen printed Ag circuit was evaluated by measuring of electrical behavior during IPC sliding test. Failure mode of the Ag printed circuits was observed by using field emission scanning electron microscope and optical microscope. Electrical resistivity of the Ag circuits screen printed on Pl substrate was rapidly decreased with increasing sintering temperature and durations. The lowest electrical resistivity of Ag printed circuit was up to $3.8{\mu}{\Omega}{\cdot}cm$ at $250^{\circ}C$ for 45 min. The crack length arisen within the printed Ag circuit after $10{\times}10^4$ sliding numbers was 10 times longer than that of after $2.5{\times}10^4$ sliding numbers. Measured insertion loss and calculated insertion loss were in good agreements each other. Insertion loss of the printed Ag circuit was increased with increasing the number of sliding cycle.

• Resources Recycling
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• v.25 no.1
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• pp.24-30
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• 2016

The study to obtain tantalum concentration from electronic components (ECs) on Printed circuit board assembly (PCBA) of laptop was conducted. Electronic components on laptop PCBA were detached from boards by using self-developed experimental apparatus. The detached electronic components were sieved and 93.2 wt.% of tantalum capacitors were concentrated from the size interval from 2.80 mm to 6.35 mm. The tantalum capacitors were pulverized by hammer mill and electrodes (anode and cathode) were removed from the grinding products by using magnetic separators under the magnetic force of 300 Gauss. Finally, tantalum concentrate was concentrated from the magnetic separator products by using Knelson concentrator, and the maximum efficiency of 76.9% was achieved under the operating condition of bowl rotating speed of 200 rpm, and fluidizing water flowrate of 7 L/min. The grade and recovery of Ta concentrate under the condition were 81.1% and 78.8%, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.338-339
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• 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 the Korean Society of Manufacturing Technology Engineers
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• v.22 no.1
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• pp.56-62
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• 2013

The laser cutting process which is flexible and rapid usually provides a better result in cutting of flexible printed circuit boards (FPCB). However, circuit-short by the re-deposition of debris from laser ablation or its heat affect zone (HAZ) on the cutting surfaces can be a problem. A laser cutting process of FPCB in the presence of liquid can minimize these negative effects. The temperature distribution of copper and polymer parts of FPCB was analyzed with numerical simulation and the experimental results were presented to evaluate this process. Generally, laser cutting under liquid has advantages of less re-deposition of carbides and less HAZ on the cutting edges. However, bubble generation and laser beam control through the liquid media should be considered carefully to obtain a successful result.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.8
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• pp.76-85
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• 2003

In this paper, a technical method for removing the solder from PCBs has been proposed to simplify the pulverizing process and to get higher quality of materials for recycling of the electronic parts in the Printed Circuit Boards (PCBs). There are several techniques to remove the solder from PCB, such as physical and chemical method, vibration, suction and blowing and so on. Among them, the suction technique turned out the best method by investigation. In the suction method, there are three variables for removing the solder. They are a temperature of the thermal wire, a velocity of moving PCB and a gap between PCB and thermal wire. To find the optimal variables for the system, an experiment has been conducted by a trial and error method. The optimal variables were found $220^{\circ}C$ of temperature, 11.58mm/s of velocity, 10mm of gap (A gap between suction hole and bottom of PCBs is 5mm). The result of the experiment shows that 50% of the solder were removed.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2439-2441
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• 2002

SMT형 인쇄회로기판 조립라인에서 SMD의 조립상태를 검사하는 검사기를 위한 경로계획 알고리즘을 제안한다. 경로계획 알고리즘은 FOV 생성 최적화와 생성된 FOV의 순서 최적화에 의하여, 검사기의 선체 검사 시간의 단축을 목표로 한다. 본 논문에서는 검사기 경로계획 문제를 수학적으로 모델링하고, 전체 검사 단계를 FOV 생성 단계와 순서결정 단계의 계층적 구조로 구성한다. 각 단계의 알고리즘은 FOV 생성 알고리즘과 TSP 알고리즘을 적용하여 구현한다. 제시된 알고리즘을 실제 검사장비에 적용하여 시뮬레이션하고, 그 유용성을 검증한다.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.1 s.61
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• pp.76-86
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• 2007