• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2179-2183
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• 2007

In this paper, to produce sheet plasma with high density for ion plating, we designed magnetic circuit of ion plating device consisting of solenoid coil and rectangular permanent magnet. And, we analyzed the effects of the magnetic field distribution using FEM (Finite Element Methode). Additionally, we made a sputtering system including ion plating technique on the basis of the design and verified the possibility of the sheet plasma application for advanced sputter system.

• Journal of the Microelectronics and Packaging Society
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• v.19 no.3
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• pp.1-7
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• 2012

Electroplating technology is widely used in semiconductor microelectronic industry. With the development of semiconductor integrated circuit to high density and light-small scale, Extremely high quality and plated uniformity of the deposited metals are needed. Simulation technique can help to obtain better plating results. Although a few plating simulation softwares have been commercialized, plating simulation is not widely prevalent in Korea. In this paper, principle of electroplating and mathematical modeling of plating simulation are discussed. Also introduced are some cases enhancing plating thickness uniformity on leadframe, PCB and wafer by using plating simulation.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.11a
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• pp.49-53
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• 2002

The Sn-Cu eutectic solder bump formation ($140{\mu}{\textrm}{m}$ diameter, $250{\mu}{\textrm}{m}$ pitch) by electroplating was studied for flip chip package fabrication. The effect of current density and plating time on Sn-Cu deposit was investigated. The morphology and composition of plated solder surface was examined by scanning electron microscopy. The plating thickness increased with increasing time. The plating rate increased generally according to current density. After the characteristics of Sn-Cu plating were investigated, Sn-Cu solder bumps were fabricated on optimal condition of 5A/dm$^2$, 2hrs. Ball shear test after reflow was performed to measure adhesion strength between solder bump and UBM (Under Bump Metallization). The shear strength of Sn-Cu bump after reflow was higher than that of before reflow.

• Journal of Welding and Joining
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• v.19 no.5
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• pp.520-525
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• 2001

The Sn-Pb eutectic solder bump formation ($150\mu\textrm{m}$ diameter, $250\mu\textrm{m}$ pitch) by electroplating was studied for flip chip package fabrication. The effect of current density and plating time on Sn-Pb deposit was investigated. The morphology and composition of plated solder surface was examined by scanning electron microscopy. The plating thickness increased wish increasing time. The plating rate became constant at limiting current density. After the characteristics of Sn-Pb plating were investigated, Sn-Pb solder bumps were fabricated in optimal condition of $7A/dm^$. 4hr. Ball shear test after reflow was performed to measure adhesion strength between solder bump and UBM (Under Bump Metallurgy). The shear strength of Sn-Pb bump after reflow was higher than that of before reflow.

• Laser Solutions
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• v.12 no.4
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• pp.6-11
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• 2009

The LDS(Laser Direct Structuring) process uses thermoplastic polymers with a additive compound that serves as plating seed after the activation by laser. It can realize industry requirement such as miniaturization of electrical component, design flexibility and reduction of production steps. The purpose of this study is to introduce LDS, and to investigate the fundamental mechanism. Also the characteristics of conductive patterns were investigated with respect to laser fluence and intensity. We have used a pulsed fiber laser (wavelength : 1064nm) and copper electroless plating to fabricate conductive patterns. The result showed that laser induced metal-organic complex was caused metalization by electroless copper plating, the critical laser fluence was $1.41\;J/cm^2$ at a scan speed of 1 m/s.

• Journal of the Korean institute of surface engineering
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• v.14 no.4
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• pp.215-220
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• 1981

The surface appearance of chromium electrodeposit was studied by employing a pulse curr-ent plating in self-regulating high speed (SRHS) bath containing 20 g/$\ell$, K2SiF6 7.5 g/$\ell$ SrSO4 and 250 g/$\ell$ CrO3. As the pulse frequency increased, the surface appearance changed suddenly from bright a-ppearance in a direct current plating condition to gray one in the range of pulse frequency less than about 20KHz. However the bright appearance is recovered as the pulse frequen-cy exceeded 20 KHz. This phenomena seemed to be related with the preferred orientation of electrodeposits, considering the relationship between the preferred orientation of elect-rodeposits and surface appearance in a SRHS bath. Direct current plating was also applied to both Sargent and SRHS bath and investigat-ion on surface appearance was extended to the high current density of 400 A/dm2. In a Sa-rgent bath, the increase in bath temperature was necessary for bright appearance as the current density was increased within 150 A/dm2, but bright region was shown in the cons-tant temperature of 70-75$^{\circ}C$ above the current density of 150A/dm2. On the other hand, two regions of surface brightness was found in a SRHS bath. One is region in the low temperature less than 25$^{\circ}C$ and the other in the moderate temperature range from 55$^{\circ}C$ to 65$^{\circ}C$.

• Journal of Plant Biotechnology
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• v.49 no.4
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• pp.331-338
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• 2022

Sunflower (Helianthus annuus L.) protoplasts were isolated from seven-day-old etiolated hypocotyls of 10 A line and four-week-old fully expanded young leaves of PI 441983 line in vitro seedlings using an enzymatic method. Purified protoplasts were collected by filtration and floatation in sucrose solution. Semi-solid protoplast culture was performed using the L4 regeneration protocol with various culture media and plating densities to achieve the highest efficiencies for protoplast culture of hypocotyl and mesophyll protoplasts of 10 A and PI 441983 lines, respectively. The concentrations in liquid L'4M medium and different plating densities were evaluated in two types of cytokinins, the adenine-type 6-benzyladenine (BA) and the phenylurea-type thidiazuron (TDZ). The highest colony formation was achieved in both sunflower lines when 0.5 mgL^-1 BA and 0.5 mgL^-1 TDZ were applied with a high plating density (3 × 10⁵ protoplasts mL^-1). These conditions led to 38.45% and 39.40% colony formation for hypocotyl protoplasts of the 10 A line and mesophyll protoplasts of the PI 441983 line, respectively. Moreover, many hypocotyl protoplast-derived colonies developed into micro-calli. In addition, superior development of both sunflower protoplasts was observed with all plating densities when BA was used in combination with TDZ. This finding will be applicable to future sunflower hybrid production via somatic hybridization.

• Journal of Power System Engineering
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• v.5 no.1
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• pp.89-96
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• 2001

Decorative property of chromium deposition from oxalic acid bath containing chromium oxide and ammonium sulfate, has been examined over a wide range of bath compositions and plating conditions. The followings were determined as optimum bath composition, $CrO_3\;200{\sim}250g/{\ell},\;H_2C_2O_4{\cdot}2H_2O\;500{\sim}700g/{\ell},\;(NH_4){_2}SO_4\;40{\sim}120g/{\ell}$, and operation conditions; pH $2.0{\sim}2.5$, current density of $15{\sim}250Adm^2 $ at the bath temperatures of $30{\sim}80^{\circ}C$. Bright chromium deposits were obtained over a wide range of ammonium sulfate concentration, bath temperature, and current density. The current efficiency decreased with increasing current density and bath pH, and increased with Increasing bath temperature. The highest current efficiency was obtained in the bath containing $80g/{\ell}$ of ammonium sulfate. Bright chromium deposits were not obtained at conditions of all the highest current efficiencies.

• Journal of the Korean institute of surface engineering
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• v.35 no.3
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• pp.141-148
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• 2002

Fe-C alloy layers were produced by pulse plating and the properties were compared with those produced by D.C. plating. When the pulse on time ($T_{on}$ ) was the same, both the duty cycle and peak current density($I_{p}$ ) had little influence on the carbon content and the hardness of the layer. The structure and hardness of the direct current plating were similar to those of the pulse current plating. However, the ductility was enhanced when the pulse current was applied due to the release of residual stress during the pulse off time($T_{off}$).).

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.723-725
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• 2001

Ion plating method using plasma is faster as several times than electron beam plating method in plating process. Recently, a variety of techniques for this method are being researched. In this paper to produce sheet plasma with high density for ion plating we designed magnetic circuit of MgO plating device consisting of solenoid coil, rectangular permanent magnet. And, we researched on the effect of those by analyzing magnetic field distribution using FEM.