• 한국표면공학회지
• /
• 제32권4호
• /
• pp.487-495
• /
• 1999

In order to form metallic electrodes on PZT (Pb (Zr, Ti)O$_3$) ceramics, plating conditions for optimal electroless Ni deposition were investigated. Pb in PZT is the major component to inhibit the electroless deposition, because it plays a active role of catalytic poison in plating solution. Adhesion of the electroless Ni deposits is measured by push-pull scale test and peel test. Results such as deposition ability, deposition rate, and thickness of deposits showed in terms of concentration of etchant, composition of catalyzing solution, and composition and pH of electroless bath solution.

• Corrosion Science and Technology
• /
• 제18권4호
• /
• pp.148-153
• /
• 2019

Pure nickel with a thickness of 1 mm was plated on type 304 stainless steels and low alloy steels (JIS G3131 SPHC) by electrolytic plating method in a circulating plating bath. Plating performance, mechanical properties, and surface characteristics were evaluated in terms of pretreatment process, anode material, pH, current density, and flow rate of the plating solution. Addition of hydrochloric acid during pre-treatment process improved the adhesion performance of plating. To improve plating efficiency, it is desirable to use S-nickel rather than electrolytic nickel. The use of S-nickel was also confirmed to be desirable for maintaining the pH and concentration of the plated solution. The defect of the plating using S-nickel anode produced pit on the surface. However, it is believed that proper control can be obtained by increasing the flow rate. Internal stress and hardness values of electrolytic nickel plating according to current density need to be carried out with further studies.

• 마이크로전자및패키징학회지
• /
• 제27권3호
• /
• pp.29-34
• /
• 2020

본 연구에서는 무전해 니켈 도금액 pH 변화에 따른 electroless nickel immersion gold (ENIG)/Sn-3.0wt.%Ag-0.5wt.%Cu(SAC305) 솔더 접합부 취성 파괴 거동에 대하여 평가하였다. ENIG 표면처리를 위한 무전해 니켈 도금액의 pH는 4.0에서 5.5로 변화 시켰다. 무전해 니켈 도금 후 Ni-P 표면 관찰 결과, 도금액의 pH가 낮아질수록 Ni-P 층 nodule 표면에 핀홀이 증가하였다. 솔더링 후 접합부 계면에서는 (Cu,Ni)6Sn5 금속간화합물이 형성되었으며, 무전해 니켈 도금액의 pH가 증가할수록 솔더접합부의 계면 금속간화합물의 두께는 증가하였다. 고속전단 시험을 통하여 ENIG/SAC305 솔더 접합부의 취성파괴 거동을 확인하였으며, 무전해 니켈 도금액의 pH가 증가할수록 솔더접합부의 전단강도는 감소하는 경향을 보였다. 또한, 솔더 접합부의 취성 파괴율은 pH가 5일 때 가장 높은 값을 보였다.

• 한국표면공학회지
• /
• 제47권5호
• /
• pp.269-274
• /
• 2014

Electroless plating process as a solution deposition method is a viable means of preparing conductive metal films on non-conducting substrates through chemical reactions. In the present study, the preparation and properties of electroless Ni-plating on flexible silicone rubber are described. The process has been performed using a conventional Ni(P) chemical bath. Additives and complexing agents such as ammonium chloride and glycine were added and the reaction pH was controlled by NaOH aqueous solution. Ni deposition rate and crystallinity have been found to vary with pH and temperature of the plating bath. It was shown that Ni-films having the high crystallinity, enhanced adhesion and optimum electric conductivity were formed uniformly on silicone rubber substrates under pH 7 at $70^{\circ}C$. The conductive Ni-plated silicone rubber showed a high electromagnetic interference shielding effect in the 400 MHz-1 GHz range.

• 한국표면공학회지
• /
• 제19권3호
• /
• pp.92-108
• /
• 1986

An electroplating on the lead frame fabricated from domestic copper plate was studied experimentally. In this study, nickel was plated on the thin copper lead frame and silver layer was coated on the nickel film in the cyanide electrolyte. The effect of process variables such as current density, plating time, coating thickness and flow rate of electrolytic solution on the properties of coating was investigated. Some samples on each step were fabricated during electroplating. The results obtained from polarization measurement, observation of SEM photograph, adhesion test of coating and microhardness test are as follows. On silver plating, polarization resistance of potentiostatic cathodic polarization curve is reduced as the flow rate of Ag electrolytic solution increases. And above resistance is also reduced when the minor chemicals of sodium cyanide and sodium carbonate are added in potassium silver cyanide bath. The reduced polarization resistance makes silver deposition on the cathode easy. An increase in the current density and the coating thickness causes the particle size of deposit to coarsen, and consequently the Knoop microhardness of the coating decreases. On selective plating an increase in the flow rate of plating solution lead to do high speed plating with high current density. In this case, the surface morphology of deposit is of fine microstructure with high Knoop hardness. An increasing trend of the adhesion of coating was shown with increasing the current density and flow rate of electrolytic solution.

• 한국표면공학회지
• /
• 제37권6호
• /
• pp.344-349
• /
• 2004

Emulsions were formed through putting small quantity of nickel electroplating solution into supercritical carbon dioxide, and then electroplating in the $sc-CO_2$ emulsions was conducted. It is an environmental-friendly technology that can solve the treatment of a large quantity of toxic plating wastewater, which is a big problem in the existing wet plating, and also can reduce secondary waste generation fundamentally. Supercritical carbon dioxide emulsions enhanced by ultrasonic horn were formed by non-ionic surfactant and nickel solution. Plating condition within emulsions was set up as 120bar and $55^{\circ}C$ through measurement of electrical conductivity following the pressure change. Experiments were conducted respectively against supercritical carbon dioxide emulsions electroplating and general chemical electroplating, and then their results were compared and analyzed. As the experiment result utilizing emulsions, plating surface was formed very evenly even with a small quantity of electroplating solution, and fine particles were plated compactly without any pinhole or crack due to hydrogenation, which occurs in general electroplating. Used electroplating solution can be reused through recovery process. Therefore, this technology will be able to be applied as new clean technology in electro-plating.

• 한국의류학회지
• /
• 제29권1호
• /
• pp.149-156
• /
• 2005

The purpose of this study was to produce the high quality of electromagnetic wave shielding fabrics. In this study, we have produced polyester fabrics by electroless Ag plating. The untreated polyester was etched with $4\%$ NaOH solution added accelerant(Benzyl Dimethyl Dodecyl Ammonium Chloride) then it was catalyzed by $SnCl_2$ solution and activated by $PdCl_2$ solution. Electroless Ag plating was carried out by changing conditions such as temperature. time, weight loss rate of polyester and kind of reducing agents. The electromagnetic wave shielding effectiveness of polyester fabric by electroless Ag plating was measured by RF Impedance Analyzer and element of electromagnetic wave shielding substance was measured using Electron probe micro analyzer. The results were as follows; The plating bath using potassium sodium tartrate by reducing agent was excellent electromagnetic wave shielding effectiveness. Element of electromagnetic wave shielding substance was silver. Electromagnetic wave shielding effectiveness was shown over 64dB at the temperature of $40^{\circ}C$, treating time 30min., weight loss rate $20\%$.

• Transactions on Electrical and Electronic Materials
• /
• 제8권6호
• /
• pp.246-249
• /
• 2007

A triple-band antenna was developed and fabricated by LDS(Laser Direct Structuring) process. The effects of the plating rate and heat treatment condition were investigated and the gains of fabricated antennas were measured at various frequencies. The laser irradiated surface shows clearly that there are prominence and depression. It shows anchoring effect between a plating material and ablation surface. The plating rate was decreased when the plating material is exhausted in the solution. This solution needs to refreshed by the new aid solution. The copper plating thickness is decreased with the increase of heat treatment temperature in the same time but it does not change other condition. The gain of LDS antenna showed higher than the generally processed antenna. This result was related with practical use of the dimension and effective dielectric constant.

• 한국표면공학회:학술대회논문집
• /
• 한국표면공학회 2000년도 추계학술발표회 초록집
• /
• pp.1-2
• /
• 2000

In chip plating, several parameters must be taken into consideration. Current density, solution concentration, pH, solution temperature, components volume, chip and media ratio, barrel geometrical shape were most likely found to have an effect to the process yields. The 3 types of barrels utilized in chip plating industry are the onventional rotating barrel, vibrational barrel(vibarrel), and the centrifugal type. Conventional rotating barrel is a close type and is commonly used. The components inside the barrel are circulated by the barrel's rotation at a horizontal axis. Process yield has known to have higher thickness deviation. The vibrational barrel is an open type which offers a wide exposure to electrolyte resulting to a stable thickness deviation. It rotates in a vertical axis coupled with multi-vibration action to facilitate mixed up and easy transportation of components. The centrifugal barrel has its plated work centrifugally compacted against the cathode ring for superior electrical contact with simultaneous rotary motion. This experiment has determined the effect of barrel vibration intensity to the plating thickness distribution. The procedures carried out in the experiment involved the overall plating process., cleaning, rinse, Nickel plating, Tin-Lead plating. Plating time was adjusted to meet the required specification. All other parameters were maintained constant. Two trials were performed to confirm the consistency of the result. The thickness data of the experiment conducted showed thatbthe average mean value obtained from higher vibrational intensity is nearer to the standard mean. The distribution curve shown has a narrower specification limits and it has a reduced variation around the target value. Generally, intensity control in vi-barrel facilitates mixed up and easy transportation of components. However, it is desirable to maintain an optimum vibration intensity to prevent solution intrusion into the chips' internal electrode. A cathodic reaction can occur in the interface of the external and internal electrode. 2H20 + e $\rightarrow$M/TEX> 20H + H2.. Hydrogen can penetrate into the body and create pressure which can cause cracks. At high intensity, the chip's motion becomes stronger, its contact between each other is delayed and so plating action is being controlled. However, the strong impact created by its collision can damage the external electrode's structure there by resulting to bad plating condition.

• 한국산학기술학회논문지
• /
• 제17권7호
• /
• pp.273-279
• /
• 2016

본 논문은 니켈-텅스텐 합금 도금 공정액에 대해 혼합 상태에서 각 공정액에 대한 농도를 정확하게 측정할 수 있는 센서 및 이를 기반으로 정밀한 농도 제어를 수행할 수 있는 제어 시스템 대한 논문이다. 최근 인쇄회로기판 시장은 전자산업의 발달로 커지고 있으며, 이에 따라 금 소비도 급격하게 증가되고 있다. 하지만 금은 비싼 원자재로 금을 대체하거나 줄이기 위한 다양한 복합 도금 공정액 개발이 이루어지고 있다. 이에 비해 복합도금 공정액을 실시간으로 측정할 수 있는 센서 개발은 아직 미진한 상태이다. 더군다나 실시간으로 도금 품질을 극대화 할 수 있도록 복합 도금 공정액 농도를 측정하고 이를 토대로 농도를 제어하기 위한 시스템은 전무한 실정이다. 이에 본 논문에서는 이러한 복합 도금 공정액에 대한 농도를 정확하게 측정할 수 있는 센서 및 농도 제어를 수행하기 위한 시스템을 개발하고자 한다. 이를 위해 분광광도법을 기반으로 복합도금 공정액 농도를 정밀하게 측정할 수 있는 센서를 개발하며 센서 농도에 대한 피드백 제어를 통해 농도를 정확하게 유지할 수 있는 시스템을 개발한다.