• 한국전자파학회논문지
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• 제11권2호
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• pp.268-277
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• 2000

이동통선 서비스가 확장됨에 따라 인접 기지국간의 간섭이 증가하고 그에 따른 IMD(Intermodulation Distortion) 문제도 증가하여 Active IMD뿐만 아니라 Passive IMD(Passive Intermodulation Distortion)에 대한 문 제도 함께 부상하고 었다. 따라서 본 고에서는 대표적인 RF 소자 중 동축선에서의 PIMD의 발생기구의 분석을 위하여 다양한 도금 두께와 도금 재질을 갖는 어랩터를 설계 및 제작하였다. 제작된 어댐터 측정결과 1M 발생 수준이 도금 재질의 전도율, 소자의 구조, 도금 재질의 두께. Aging현상 등에 의존함을 확인하였으며, 도금 두께의 변화와 재질의 변화를 통해 PIMD 발생기구를 분석하였고, PIMD의 제어기술 방안을 검토하였다.

• 한국표면공학회지
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• 제18권3호
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• pp.105-115
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• 1985

Lead-tin-copper ternary alloy electrodeposition is conducted onto the inner bore surface of plain bearings as an overlay in order to investigate the effect of slot width, current density and fluoboric acid concentration on the uniformity of overlay. The thickness of overlay is analyzed by means of current distribution resulting from the overvoltage of plating bath and the apparent distance between cathode and anode. The result demonstrate that the uniformity of overlay is remarkably dependent of the slot size and current density, but has little bearing on the fluoboric acid concentration over 100g/L. This present study indicates that uniform overlay is obtainable within the tolerable thickness of ${\pm}2{\mu}m$ by using the slot width of 22mm. The surface morphology examination also shows the important role of concentration polarization of the micro-uniformity of overlay. The micro-uniformity has improved at the low concentration polarization which resulted from operating at the low current density and high fluoboric acid concentration. The surface morphology of deposits exhibits the vivid pyramid crystalline in the plating condition of low concentration polarizatio and all deposits have columnar structure parallel to the applied electric field regardless of the electroplating condition used.

• 한국자기학회지
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• 제6권3호
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• pp.145-150
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• 1996

Ferrite plating 방법은 진공이 불필요하고, 저온(< $100^{\circ}C$)에서 페라이트 박막을 제작할 수 있다. 이 방법으로 유리 기판위에 $80^{\circ}C$에서 $Fe_{3-x}Mn_{x}O_4(x=0.0~0.023)$의 페라이트 박막을 제작하였다. 박막은 60분간 성장시켰으며, 막의두께는 약 $9000\AA$이었고, 거울면과 같은 광택을 지녔다. X-선 회절 실험으로 스피넬 구조의 단일상을 확인하였다. $Fe_{3-x}Mn_{x}O_4$ 박막의 구성비 x는 반응용액에서의 구성비 x'에 비해 매우낮다(x/x'=0.04). $Fe_{3}O_{4}$ ferrite 박막의 포화자화($M_{s}$)는 480 emu/cc로써 bulk 시료와 비슷한 값을 가졌다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.152-152
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• 2009

We investigate micro-tip properties as Ni-Co plating and CMP processes for MEMS probe card and units. The micro-tip are fabricated by using Ni-Co plating machine, lapping machine, and chemo-mechanical polisher. In order to get high conductive and reliable micro-tip, we control Co contents and thickness by CMP speed. We have found that about 20-25% of Co contents are required and have to lapping speed of 30 rpm. Also, we investigate photolithography and Ni-Co plating processes conditions for the one-step and the three-step micro-tips.

• 한국재료학회지
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• 제11권11호
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• pp.941-946
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• 2001

Conductive microspheres with a density of 0.2 g/cc were fabricated by electroless silver plating for application to the light-weighted microwave absorbers. The silver plating was conducted with the variation of plating conditions (sensitizing condition, $AgNO_3$, concentration, amount of reducing agent). Specimens have very low electro-resistivity. Under an optimum processing condition, conductive microspheres with uniform silver plating layer can be produced. Rubber-sphere composites were fabricated and their microwave absorbing properties were measured by HP8722D Network Analyzer. It was found that the lower the electrical resistance of microsphere, the better the microwave absorbing properties. Feasibility of microwave absorbers using this microspheres can be demonstrated with the result of microwave reflection loss of -15 dB and thickness of 1.44 mm.

• 한국분말재료학회지
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• 제22권2호
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• pp.134-137
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• 2015

The monolayer engineering diamond particles are aligned on the oxygen free Cu plates with electroless Ni plating layer. The mean diamond particle sizes of 15, 23 and $50{\mu}m$ are used as thermal conductivity pathway for fabricating metal/carbon multi-layer composite material systems. Interconnected void structure of irregular shaped diamond particles allow dense electroless Ni plating layer on Cu plate and fixing them with 37-43% Ni thickness of their mean diameter. The thermal conductivity decrease with increasing measurement temperature up to $150^{\circ}C$ in all diamond size conditions. When the diamond particle size is increased from $15{\mu}m$ to $50{\mu}m$ (Max. 304 W/mK at room temperature) tended to increase thermal conductivity, because the volume fraction of diamond is increased inside plating layer.

• 마이크로전자및패키징학회지
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• 제15권2호
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• pp.17-21
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• 2008

Sn-Cu계 솔더 범프에서 무전해도금법을 이용한 범프 형성에 대한 연구를 하였다. $20{\mu}m$ via에 전기도금법으로 구리를 채운 웨이퍼 위에 ball형태의 범프를 형성하기 위하여 구리와 주석을 도금하여 약 $10{\mu}m$높이의 범프를 형성하였다. 구리 범프 형성 시 via위에 선택적으로 도금하기 위하여 활성화 처리 후 산세처리를 실시하고 무전해 도금액에 안정제를 첨가하였다. 무전해도금법을 이용하여 주석 범프 형성 시 도금층이 구리 범프에 비해 표면의 균일도가 벌어지는 것으로 관찰되었지만 reflow공정을 실시한 후 ball 형태의 균일한 Sn-Cu 범프를 형성하였다.

• 한국정밀공학회지
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• 제26권6호
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• pp.114-121
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• 2009

Mobile phone is a representative personal communication tool among wireless communication devices. Recently, with the miniaturization and light-weight trend of mobile phone, the vibration motor has been replaced by coin type. The required performances of coin type vibration motor needed by user are long life, higher vibration, and thin thickness. Also the most important factor determines the performance of vibration motor is long-term reliability, which is mainly related to PCB plating technique for commutator. In this study, three types of fault were categorized to analyze the cause for malfunction of vibration motor. And, hardness and surface morphology on plating surface are also investigated to optimize the plating method and plating conditions. As a result, new plating method and conditions were proposed to increase the durability of PCB commutator.

• 한국재료학회지
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• 제11권10호
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• pp.820-832
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• 2001

In order to obtain the basic data on the optimum conditions of electroforming process for fabricating the micro wiring pattern for plate type micro- motor core, characteristics of plating bath and properties of deposits were studied with various copper plating baths which contain sulfate, fluoborate, pyrophosphate and cyanide salt, respectively. Cathodic polarization, throwing power, internal stress, texture and surface morphology of deposits were observed. Throwing power of plating solution is deeply related to the polarization curves and the values are in the range of +20∼20%. The order of values ate as follows- pyrophosphate, cyanide, sulfate and fluoborate bath. Internal stresses of deposits are tensile in all of the copper plating bath. Thickness of the deposits plated at the center of holes has the highest value in the pyrophosphate bath and K factor, ratio of height and width of deposit, is 1.44. It was confirmed that the pyrophosphate bath was the best one for the electroforming of wire pattern.

• 한국표면공학회지
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• 제35권5호
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• pp.295-304
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• 2002

In this study, the effect of the diameter and the number of barrel hole on the total area of barrel hole were calculated and analyzed. And the effects of applied current density, rotational speed of the barrel, size and number of barrel hole, and the volume of plating materials on the distribution of plating thickness were experimented and discussed by the barrel electroplating of the tube type brass specimens in a sulfamate nickel barrel solution. The effect of barrel hole size and barrel hole area on the throwing power was also discussed.