• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.1
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• pp.52-56
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• 2006

This paper presents a cross-eye characteristics of multi-path wave scattering. Cross-eye method uses the phase differences of multi signals and is used fur electronic protection. When a signal is propagated from transmitter to receiver on the ground surface, direct wave and reflected wave signals are combined in front of the receiving antenna with different phases. To calculate and control the amplitude and phase of reflected signal, we have developed a cross eye electronic protection method for radar system and studied the variation of electric power density.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1546-1547
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• 2006

오늘날 전자기파의 영향은, 제어장비의 내부에 있는 기판의 전자 부품에 전자기적인 충격을 주어 장비의 오동작이나 고장을 일으키는 등 심각한 문제들이 제기 되고 있다. 이러한 임펄스 전자기파는 제어 장치에 연결된 제어전선으로 타고 들어와서 전자장비 내부의 부품들과 반사,공진등을 일으켜서 결국에는 PCB(printed circuit board)에 손상을 입혀서 그 장치들을 사용 못하게 할 수가 있다. 주파수가 광대역인 50MHz 에서 800MHz 까지의 EMI(electro magnetic interference)환경을 만들 수 있는 장치를 제작 하였다. 이러한 UWB(ultra wide band)장치는 고전압펄스를 압축 성형하여, 동작시간이 아주 빠른 ultra fast 스위치를 통해서, 펄스의 기림 시간이 수백ps의 파형을 만들어, 안테나로 전송하여 공간으로 방사시키는 장치에 대해 설계 제작하여 실험한 결과에 대해 논하고자 한다.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1366-1367
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• 2006

Embedded capacitor technology is one of the effective packaging technologies for further miniaturization and higher performance of electric package systems. So we used the 3D EM simulator for embedded capacitor design in 8-layed PCB(Printed Circuit Board). The designed capacitors value are 2 pF, 5pF, 10 pF, respectly. we investigated characteristics of capacitance - frequency and SRF(Self Resonance Frequency) as changing the rate of hight and width of upper pad of embedded capacitors.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.217-218
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• 2007

Aluminum 분말과 고분자를 혼합하여 고분자-금속 복합재료(polymer-metal composite)를 만들어 copper foil과 기판의 접착력을 평가하였다. Tape casting 방법을 이용하여 sheet 만들고 vacuum lamination으로 PCB(Printed Circuit Board)기판을 제조한 후 포토공정으로 peel strength pattern을 형성하였으며, 본 연구에서는 최적의 aluminum 조건을 찾기 위하여 압력, 온도, copper foil의 표면 상태와 silane 표면 코팅에 따른 aluminum-polymer복합재료의 peel strength의 변화를 확인하였다. 최적의 조건은 silane 표면 코팅 처리를 한 aluminum 분말로 $210^{\circ}C$에서 $9.7kg/cm^2$ 압력으로 matte면의 돌기 크기가 크며, 응집이 잘 되어있는 copper foil을 사용하여 13.89N의 우수한 peel strength를 구현 할 수 있었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.349-349
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• 2005

수동소자를 PCB(Printed Circuit Board) 안으로 집적하기 위한 방법의 일환으로 polymer-metal, polymer-ceramic composite에 연구가 국내외 연구 국내외 연구기관에서 광범위하게 진행되고 있다. 본 연구에서는 polymer-metal-ceramic composite 에서 PZT-coated Ni의 volume fraction에 따른 유전율 변화에 대하여 조사하였다. 원료로는 PZT(52/48) solution. 니켈금속분말, PMMA(polymethyl methacrylate)를 사용하였다. 전기적 특성은 임피던스분석기를 이용하여 측정하였으며 mixing rule과 percolation theory를 이용하여 결과를 해석하였다.

• Journal of the Korean Society of Industry Convergence
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• v.12 no.4
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• pp.215-219
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• 2009

A packaging technology based on flip-chip bonding and Pb-free solder for silicon pressure sensors on printed circuit board (PCB) is presented. First, the bump formation process was conducted by Pb-free solder. Ag-Sn-Cu solder and the pressed-screen printing method were used to fabricate solder bumps. The fabricated solder bumps had $189-223{\mu}m$ width, $120-160{\mu}m$ thickness, and 5.4-6.9 standard deviation. Also, shear tests was conducted to measure the bump shear strength by a Dage 2400 PC shear tester; the average shear strength was 74 g at 0.125 mm/s of test speed and $5{\mu}m$ shear height. Then, silicon pressure sensor packaging was implemented using the Pb-free solder and bump formation process. The characteristics of the pressure sensor were analogous to the results obtained when the pressure sensor dice are assembled and packaged using the standard wire-bonding technique.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.10
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• pp.146-153
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• 1996

This paper presents the development of a collocated capacitance sensor and its application to the controller design for magnetic bearing supported rotor systems. The main feature of the sensor is that it is made of a compact printed circuit board(PCB) so that it can be built into the actuator coil of the magnetic bearing unit. The singnal processing unit hax been also developed. The experi- mental results of the sensor performance evaluation on sensitivity, bandwidth and resolution are presented. Then, simulation study shows the advantages of the collocated sensor for magnetic bearings over the nonco- llocated sensor. Finally, the experimental result on the performance of the collocated sensor based contrl- ler for a magnetic bearing rotor system is presented.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.8
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• pp.106-113
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• 1995

Surface mounters are used to mount the parts of electronic products on PCB(Printed Circuit Board. Those machines rely on high precision, high productivity, and software for accomodation of use. In this paper, two algorithms and a software which can give the users the acco-modation and high productivity for rotary type surface mounters are presented. The algo- rithms for development of of the software consider all factors which affect the effeciency of the operation. And the interface between user and machine for the accomodation of use can be achieved through the developed software.

• Journal of Advanced Navigation Technology
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• v.17 no.2
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• pp.177-182
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• 2013

In this paper, printed antenna which can be applied to a built-in wireless module of the security controller operating at global positioning system(GPS) L1 frequency band(1.575GHz) is proposed. The proposed antenna is basically composed of a microstrip patch antenna with inserting feed. In particular left and right slots which are respectively asymmetric are used for impedance matching, whereas slot with one open-end and shorting point are used on the bottom plane to set operating frequency and enhance bandwidth. It is observed at the desired GPS L1 frequency band that the radiation efficiency and gain of the proposed antenna are 90% and more than 4.8dBi respectively.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.9
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• pp.26-34
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• 1998

This paper presents a characterization method for faults of circuit patterns on MCM(Multichip Module) or PCB(Printed Circuit Board) substrates with electron beams of a SEM(Scanning Electron Microscope) by inducing voltage contrast on the signal line. The experimentation employes dual potential electron beams for the fault characterization of circuit patterns with a commercial SEM without modifying its structure. The testing procedure utilizes only one electron gun for the generation of dual potential electron beams by two different accelerating voltages, one for charging electron beam which introduces the yield of secondary electron $\delta$ < 1 and the other for reading beam which introduces $\delta$ > 1. Reading beam can read open's/short's of a specific net among many test nets, simultaneously discharging during the reading process for the next step, by removing its voltage contrast. The experimental results of testing the copper signal lines on glass-epoxy substrates showed that the state of open's/short's had generated the brightness contrast due to the voltage contrast on the surface of copper conductor line, when the net had charged with charging electron beams of 7KV accelerating voltages and then read with scanning reading electron beams of 2KV accelerating voltages in 10 seconds. The experimental results with Au pads of a IC die and Au plated Cu pads of BGA substrates provided the simple test method of circuit lines with 7KV charging electron beam and 2KV reading beam. Thus the characterization method showed that we can test open and short circuits of the net nondestructively by using dual potential electron beams with one SEM gun.