• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2001년도 추계학술발표회 초록집
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• pp.56-56
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• 2001

Ni-W alloy deposit is one of the best alternatives to hard chromium plating because of its good mechanical properties (high hardness, high strength, and good wear resistance). Ni-W alloy is deposited from weakly acidic or alkaline electrolytic bath with nickel sulfate, sodium tungstate or APT, and some kinds of organic hydroxy-acid complex and ammonia salts. W content of the deposit can be changed from 0 to 5Owt% and the coating with high W content is more attracted. But, meanwhile, the deposited layers are always found high internal stress, which cause them to become brittle and to bond insufficiently with the substrate. On the second hand, as the W content is incresed, the current efficiency reduced, which results in large quantities of hydrogen evolution and then produces bubbles on surface and pitting appearance In this paper, the influence of some additives on Ni-W alloy electroplating was investigated by means of compositional analysis and SEM. The initial results showed that 2-butyne-1,4-diol was the best brightener for Ni-W plating process. It could brighten and level deposit, but decreased the cathodic current efficiency. Its optimum concentration range is from O.lgjL to 0.5gjL. Besides, three kinds of additives including 2-butyne-1,4-diol were examined with Dagguchi method.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2008년도 추계학술대회 초록집
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• pp.15-16
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• 2008

In case manufacturing COF, through hole should be made to be used for a pathway connecting the conductive layers of its both faces. In case Cu-plating inside of through hole with electroless plating way, contact between Cu and PI film gets bad to be fell apart from PI by the impact of applying to the electric devices. Therefore, after sputtering is applying on inner through hole, then a method to perform electroplating process. In this study, after changing sputtering condition to manufacture FCCL, we looked the changeability of the upper PI and inner hole Cu layers. Making use of RF Magnetron sputtering equipment, we coated Cu thin film and Cu-plated on it through electroplating. After cold-mounting the completed FCCL, we examined hole section through an optical microscope. From the result of test, with parameters deposition pressure and deposition time, both the thickness of the hole plated layer and PI plated upper layer increased at regular rate, increasing the thickness of Cu sputter layer. However, from the result of test in increasing RF-power, we could know the increment rate of hole plated layer is considerably greater than that of PI plated upper layer. Therefore, we finally acquired good result; if you want only to increase the plated layer of inner hole, it's much better to increase RF-power.

• 한국표면공학회지
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• 제45권2호
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• pp.81-88
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• 2012

Probe tip, which should have not only superior electrical characteristics but also good abrasion resistance for numerous contacts with semiconductor pads to confirm their availability, is essential for MEMS probe card. To obtain good durability of probe tip, it needs thick and crack-free rhodium layer on the tip. However, when the rhodium thickness deposited by electroplating increased, unwanted cracks by high internal stress led to serious problem of MEMS probe tip. This article reported the method of thick Rh deposition with Au buffer layer on the probe tip to overcome the problem of high internal stress and studied mechanical and electrical properties of that. MEMS probe tip with double-Rh layer had good contact resistance and durability during long term touch downs.

• 대한기계학회논문집A
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• 제28권11호
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• pp.1794-1798
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• 2004

We present a fabrication method of high aspect ratio 100nm-scale nickel stamper using e-beam writing for the injection molding of optical grating patterns. Conventional nickel stamper is fabricated by nickel electroplating process which is followed by seed layer deposition. In this paper, we have used chrome coated blank mask without anti-reflection layer of CrON in order to simplified electroplating process. In experimental study, we have optimized electron-beam dosage for 100nm-scale optical grating patterns with 2.5-aspect ratio, and fabricated nickel stamper using above grating patterns as PR mold. Fabricated nickel stamper have showed height of 240$\pm$20nm and width of 116$\pm$6nm.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2007년도 추계학술발표대회 및
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• pp.26.2-26.2
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• 2007

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1971-1973
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• 1996

In this paper various types of gyroscope fabricated by micromachining technologies were reviewed. Four common types of gyroscope reported in the past few years are beam, tuning fork, gimbal, and vibrating shell structure made by surface micromachining using sacrificial layer, bulk micromachining using RIE, or electroplating method. In the study of these new gyroscopes, the fabrication methods, advantages and disadvantages of each structure were examined as well as the direction of development in the future.

• 보존과학연구
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• 통권15호
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• pp.52-58
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• 1994

To protect corrosion of bronze roofing tile for Choson Royal Historic Museum, lead coating on tile was performed by electroplating method with thickness of $35\mum$. Lead coated tile samples were inverstigated what corrosion products were formed with color changes on them by testing Accelerated Weathering. No sulfides were formed on samples contacting with 300ppm sulfur dioxide and any color changes were not found. In Accelerated Weathering test, White hydrocerussite, basic lead carbonate($2PbCO_3Pb(OH)_2$) having protective structure made of compact adhering crystals.

• 한국표면공학회지
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• 제54권3호
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• pp.158-163
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• 2021

Some studies on electrochemical additive manufacturing of metals were summarized in this technical report, and development status of selective electrochemical 3D printing technology was introduced. In order to apply it to the PCB mass production process, essential considerations how to overcome the fundamental problems, such as the sizing, process sequence and PCB process design have been described.

• 전기화학회지
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• 제2권3호
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• pp.138-143
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• 1999

최근 large scale integrated circuits(LSI) 및 printed circuit board(PCB)의 세밀화가 전자기기의 소형화로 인하여 필수 불가결하게 되었다. 전해 도금은 LSI및 PCB의 전도도 및 부식저항을 향상시키기 위해서 전도성 라인의 말단에 적용되고 있다. 그러나 회로 기판의 소형화 및 고직접화로 인하여 적용되지 못하고 있다. 따라서 최근 무전해 도금은 복잡한 장치와 외부에서 전원을 필요치 않는 작동의 간편함 때문에 매우 각광 받고 있는 방법 중의 하나이다. 본 연구는 무전해 니켈/금도금의 도금 기술 개발을 위해 시험하였다. 무전해 니켈 도금은 $85^{\circ}C$의 도금 욕에서 PCB기판 위에 침적 시켰고 그 다음 금층은 동일한 방법으로 $90^{\circ}C$에서 니켈 층위에 침적 시켰다. Bonderbility는 무전해 니켈/금도금의 안정성을 평가하기 위해 gold wire 또는 solder ball 테스트로 실험하였다.

• 반도체디스플레이기술학회지
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• 제13권3호
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• pp.51-55
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• 2014

Ni-CNT(Carbon Nanotubes) composite coating is often used for the surface treatment of mechanical/electronic devices to improve the properties of the Ni coating. For the Ni-CNT coating, the dispersion of CNT fibers is a critical process. In this study, ultrasonic treatment instead of the conventional ball milling was attempted as a dispersion method for the electroless Ni-CNT coating. SEM-EDX analysis was performed and contact angle, sheet resistance, and micro-hardness were measured. Results showed that the ultrasonic treatment was comparable to the ball milling, as a dispersion method, but the difference was negligible. However, combined ball milling and ultrasonic treatment(double treatment) showed much improved micro-hardness value, above 350Hv(close to the value obtained by the Ni-CNT electroplating). In addition, electroless Ni-CNT(double-treated) coatings formed on the thin Ni film deposited by the electroless plating(double coating) showed better mechanical properties. Thus, double treatment and double coating are suggested as an improved electroless Ni-CNT coating method.