• Title/Summary/Keyword: Plating technique

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Electroless plating of buried contact solar cell (전극함몰형 태양전지의 무전해도금)

  • Dong Seop Kim;Eun Chel Cho;Soo Hong Lee
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.6 no.1
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    • pp.88-97
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    • 1996
  • The metallization is the key to determining cell costs, cell performance, and system reliability. Screen printing technology suffers from several limitations affecting mainly the front grid. The buried contact solar cell (BCSC) was specifically desinged to be compatible with low cost, mass production techniques and avoid the conventional metallization problem. By using electroless plating technique, we performed this metallization inexpensively and reliably. This paper presents the details of the optimization procedure of metallization schemes on laser grooved cell surfaces. Commercially available Ni, Cu and Ag plating solutions were applied for the cell metallization. The application of those solutions on the buried contact front metallization has resulted in an cell efficiency of 18.8%. The cell parameters are an open circuit voltage of 651 mV, short circuit current density of 37.1 mA/$\textrm{cm}^2$, and fill factor of 77.8 %. The efficiency of over 18 % was achieved in the above 90% of the batch.

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연구논문 초록(1967~1978)

  • 한국표면공학회
    • Journal of Surface Science and Engineering
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    • v.16 no.4
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    • pp.199-214
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    • 1983
  • Up to this date, numerous methods of analysis of electroplating solutions are published. Some, however, need lots of works before reaching final results, or require high technique and special instruments, and also some are unaccurate due to unclearnes of end point. Like our undevelope countries, technicians of electoplating shops are most high school gradutes or under, and have not much knowledge on chemistry. Furthermore, those technicians have to control their plating solutions by themselves without having enough analytical laboratory equiIJment. Therefore, in this paper the simplest, besides accurate method is investigated after comparing nu.merous methods published. Among the methods of 'copper determinations from acid and alkaline copper plating baths, EDT A titration method are chosen, due to these methods are the simplest and fastest for the evaluation of metal content, without requiring any special instrument. For acid copper solutions, chelate titrations were accurate enough. Since the end point of titration of chelate method is variable according to the kind of .indicators androther metal's coexsistence as well as solution comIJonent, many difficulties were encountered from cyanide' copper, on the contrary of acid copper bath. PAN, PV, and MX indicators were tried, but it is found that MX is the best. In cyanide solution, due to cyanide is the masking reagent, elimination of this component is essential, and finally found that elimination eN- by precipitation with AgN03 solution was the simplest and the most accurate way among others. This method was very accurate for the new plating solutions even coexistence with organic brightners. However used solutions for long months running have to be predetermined the accurate copper value by thiosulfate method from time to time, before chelate titration by means of AgN03 precipitation. Always some constant deviatioJ;ls will be seen according to the solutions nature. Therefore those deviation values have to be compensated each time.

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Cr Electroplating Technology to prevent Interdiffusion between Metallic Fuel and Clad Material (금속연료-피복재 상호확산 방지를 위한 크롬 도금법 적용 연구)

  • Kim, Jun Hwan;Lee, Kang Soo;Yang, Seong Woo;Lee, Byoung Oon;Lee, Chan Bock
    • Korean Journal of Metals and Materials
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    • v.49 no.12
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    • pp.937-944
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    • 2011
  • Studies have been carried out in order to reduce fuel-cladding chemical interaction (FCCI) behavior of metallic fuel in sodium-cooled fast reactors (SFR) using an electroplating technique. A $20{\mu}m$ thick Cr layer has been plated by the electrochemical method in the Sargent bath over the HT9 (12Cr-1Mo) clad material and diffusion couple tests of the U-10Zr metallic fuel as well as the rare earth alloy (70Ce-29La) have been conducted. The results show that the Cr plating can prevent FCCI behavior along the fuel-clad interface. However, cracks developed through the thickness during plating, which resulted in the migration of some fuel constituents. Variation of bath temperature, application of pulse current, and post heat treatment have been conducted to control such cracks. We found out that some conditions like the pulse current and the post heat treatment enhanced the layer property by reducing the internal cracks and improving the diffusion couple test.

Effect of Oxygen on the Microstructure and Mechanical Properties of Cr-O-N Coatings (Oxygen 함량에 따른 Cr-O-N 코팅막의 미세구조 및 기계적 특성에 관한 연구)

  • Yun, Jun-Seo;Kwon, Se-Hun;Park, In-Wook;Lee, Jeong-Du;Kim, Kwang-Ho
    • Journal of Surface Science and Engineering
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    • v.42 no.5
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    • pp.220-226
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    • 2009
  • Cr-O-N coatings having different oxygen contents were deposited on Si wafer and SUS 304 substrates by an arc ion plating technique using Cr target in $Ar/O_2/N_2$ gaseous atmosphere. As increasing oxygen content in the coating, the microstructure of Cr-O-N coating changed from polycrystalline having NaCl structure to amorphous structure. Further increase of oxygen content resulted in phase transformation from amorphous to rhombohedral structure. From the variations of d value and average grain size, it was revealed that the maximum solubility of oxygen in Cr-O-N coating was about 21 at.%. And the maximum micro-hardness of 2751HK was obtained in this composition. The lowest friction coefficient was measured in the coating having 34.8 at.% of oxygen. However, more narrow width of wear track was found in the coating having 30.1 at.% of oxygen.

In-Situ Optical Monitoring of Electrochemical Copper Deposition Process for Semiconductor Interconnection Technology

  • Hong, Sang-Jeen;Wang, Li;Seo, Dong-Sun;Yoon, Tae-Sik
    • Transactions on Electrical and Electronic Materials
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    • v.13 no.2
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    • pp.78-84
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    • 2012
  • An in-situ optical monitoring method for real-time process monitoring of electrochemical copper deposition (CED) is presented. Process variables to be controlled in achieving desired process results are numerous in the CED process, and the importance of the chemical bath conditions cannot be overemphasized for a successful process. Conventional monitoring of the chemical solution for CED relies on the pH value of the solution, electrical voltage level for the reduction of metal cations, and gravity measurement by immersing sensors into a plating bath. We propose a nonintrusive optical monitoring technique using three types of optical sensors such as chromatic sensors and UV/VIS spectroscopy sensors as potential candidates as a feasible optical monitoring method. By monitoring the color of the plating solution in the bath, we revealed that optically acquired information is strongly related to the thickness of the deposited copper on the wafers, and that the chromatic information is inversely proportional to the ratio of $Cu$ (111) and {$Cu$ (111)+$Cu$ (200)}, which can used to measure the quality of the chemical solution for electrochemical copper deposition in advanced interconnection technology.

Low-cost Contact formation of High-Efficiency Crystalline Silicon Solar Cells by Plating

  • Kim D. S.;Lee E. J.;Kim J.;Lee S. H.
    • New & Renewable Energy
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    • v.1 no.1 s.1
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    • pp.37-43
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    • 2005
  • High-efficiency silicon solar cells have potential applications on mobile electronics and electrical vehicles. The fabrication processes of the high efficiency cells necessitate com placated fabrication precesses and expensive materials. Ti/Pd/Ag metal contact has been used only for limited area In spite of good stability and low contact resistance because of Its expensive material cost and precesses. Screen printed contact formed by Ag paste causes a low fill factor and a high shading loss of commercial solar cells because of high contact resistance and a low aspect ratio. Low cost Ni/Cu metal contact has been formed by using a low cost electroless and electroplating. Nickel silicide formation at the interface enhances stability and reduces the contact resistance resulting In an energy conversion efficiency of $20.2\%\;on\;0.50{\Omega}cm$ FZ wafer. Tapered contact structure has been applied to large area solar cells with $6.7\times6.7cm^2$ in order to reduce power losses by the front contact The tapered front metal contact Is easily formed by the electroplating technique producing $45cm^2$ solar cells with an efficiency of $21.4\%$ on $21.4\%\;on\;2{\Omega}cm$ FZ wafer.

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Fabrication of EDM Electrodes by Localized Electrochemical Deposition

  • Habib, Mohammad Ahsan;Gan, Sze Wei;Lim, Han-Seok;Rahman, Mustafizur
    • International Journal of Precision Engineering and Manufacturing
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    • v.9 no.2
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    • pp.75-80
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    • 2008
  • The fabrication of complex three-dimensional electrodes for micro electrical discharge machining (micro-EDM) is an important issue in the field of micromachining Localized electrochemical deposition (LECD) is a simple and inexpensive technique for fabricating micro-EDM electrodes. This study presents a new process for manufacturing electrodes with complex cross-sections using masks of different shapes, In this process, a non-conductive mask is placed between an anode and cathode that are immersed in a plating solution of acidified copper sulfate. The LECD is achieved by applying a pulsed voltage between the anode and cathode, which are separated by a small distance. In this setup, the cathode is placed above the anode and the mask, so that the deposited electrode can be used directly for EDM without changing the tool orientation. We found that the microstructure of the deposited electrode is influenced by the concentration of the plating solution and organic additives. Moreover, the values of the voltage, frequency, and duty cycle of the pulsed input have significant effects on the microstructure of the fabricated electrode. Finally, the optimum values of the voltage, frequency, and duty cycle were determined for the most effective fabrication of complex-shaped electrodes.

Study on Nickel Plating of Leadframe using Pulse Technique (펄스법을 이용한 리드프레임의 니켈도금에 관한 연구)

  • Chung W.S.;Min B.S.;Lim J.J.;Chung U.C.
    • Journal of Surface Science and Engineering
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    • v.36 no.3
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    • pp.242-250
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    • 2003
  • Electrodeposition of Ni was carried out on copper substrate from Ni Sulfamate bath by DC and high frequency pulse current. During the electroplating, bath temperature was steady $60^{\circ}C$ , agitation was applied. Morphology and surface roughness of electrodeposits was investigated with the AFM. Crystalline structure of electrodeposits was investigated with XRD. Also, surface electric resistivity was investigated with 4-point probe. The result of crystalline structure by X-ray diffractometer, in the case of DC, <200> direction was dominant growing direction. But in the case of PC, the ratio of <200> direction vs. other direction decreased. As the pulse frequency increased, the enhanced properties of deposits were shown. With increasing frequency, the degree of surface properties increased DC more than that of PC, eg surface morphology, roughness and the degree of compactness of grains. With increasing duty cycle, the surface properties such as the degree of the morphology, roughness and electroconductivity was deteriorated.

A Study on the Enhancement of Corrosion Resistance of Magnesium Alloy by Dry Plasma Process (건식플라즈마 표면처리법에 의한 마그네슘 합금의 내식특성 향상)

  • Yun, Yang-Sup
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.17 no.2
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    • pp.155-160
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    • 2011
  • In these days, there are increasing demands for weight reduction in many industrial fields including marine industries. Therefore, magnesium thin films for lightweight materials were prepared on magnesium alloy substrate. The influence of gas pressure and substrate bias voltages on the crystal orientation and morphology of the films was determined by using X-ray diffraction and FE-SEM, respectively. And the effect of crystal orientation and morphology of the magnesium thin films on corrosion behavior was estimated by measuring electro-chemical anodic polarization curves in deaerated 3% NaCl solution. From the results, corrosion resistance of Mg thin films was improved by controlling the crystal orientation and morphology of the films with effective use of plasma ion plating technique.

Study on the Hydrogen Delayed Fracture Property of TRIP Steel by Slow Strain Rate Testing Method (일정 변형률 시험에 의한 TRIP강의 수소 지연파괴 특성연구)

  • Cho, J.H.;Lee, J.K.
    • Corrosion Science and Technology
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    • v.10 no.4
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    • pp.131-135
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    • 2011
  • The demands of high-strength steel have been steadily increased to reduce the weight of vehicles. Although the TRIP steel has been the promising candidate material for the purpose, high strength hinders the application due to the susceptibility to hydrogen delayed fracture in the corrosive environment. Moreover, the testing method was not specified in the ISO standards. In this work, the test method to evaluate the susceptibility of hydrogen delayed fracture was studied by slow strain rate testing technique. The four test experimental parameters were studied : strain rate, hydrogen charging time, holding time after hydrogen charging, and holding time after cadmium plating. The steel was fractured by hydrogen in case the strain rate was in the range of $1{\times}10^{-4}{\sim}5{\times}10^{-7}/sec$. It was confirmed that the slow strain rate test is effective method to evaluate the susceptibility to hydrogen delayed fracture. The holding time over 24 hrs after hydrogen charging, nullified the hydrogen effect, that is, the specimen was no more susceptible to hydrogen after 24 hrs even though the specimen was fully hydrogen-charged. Moreover, cadmium electroplating could not prevent from diffusing out the hydrogen from the steel in the experiment. The effective experimental procedures were discussed.