• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.311-312
• /
• 2005

Applying a designed test coupon pattern for fabricating resistors various resistors were formed using PTF(polymer thick film) pastes. Aspect ratio from 0.25 to 4 were selected for fabricating resistors. Formed resistors were cured at $170^{\circ}C$ and $240^{\circ}C$. Electrical properties of fabricated resistors were measured and their values analyzed in relation to cure temperature and formed geometry via printing. Also effects of substrates used for fabricating resistors were observed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.25 no.11
• /
• pp.926-929
• /
• 2012

The $Sr_{0.7}Bi-{2.3}Nb_2O_9$(SBNO) thin films were deposited on Si substrate by RF magnetron sputtering method at $300^{\circ}C$ of substrate temperature. And the SBNO thin films were annealed at $650{\sim}800^{\circ}C$ using RTA (rapid thermal annealing). The grain of SBNO thin films were increased with the increase of annealing temperature. The dielectric constant (100) of SBNO thin film was obtained by RTA above $750^{\circ}C$. The voltage dependence of dielectric loss showed a value within 0.03 in voltage ranges of -5~+5 V. Also, the dielectric constant characteristics showed a stable value with the increase of frequency.

• Journal of the Korean Vacuum Society
• /
• v.9 no.1
• /
• pp.60-68
• /
• 2000

The optical constants ($E_g^d$, n, K) of the polycrystalline CdSe thin films deposited on the glass substrate by the electron-beam evaporation technique are determined over 400~2,500 nm photon wavelengths. In order to explain the variation of the optical contents with film thickness and substrate temperatures, the surface microstructural parameter are investigated by AFM (atomic forced microscope( images for the films deposited by different growth conditions. It is shown that the variations of optical constants are close related to changes of the surface morphology of the CdSe thin films. The decrease in the band gap with film thickness is connected with quantum size effects due to increase of the grain size. The refractive index of CdSe films decrease with increasing the grain size of the films, and the dispersion of the refractive index followed a single oscillator model according to the Sellmeier formulation.

• Journal of Welding and Joining
• /
• v.17 no.2
• /
• pp.61-65
• /
• 1999

Because of the need for packages which accommodate high pin count, high density and high speed device, PBGA(plastic ball grid array) package gets more spotlight. But the substrate material which is used for PBGA package is in nature susceptible to moisture penetration. The objective of the study is to find out the path of delamination in the stacked structure of substrate. To increase the adhesion between the cooper laminate and PSR(photo solder resist) which is the weakest part, experiments were performed by changing parameters of printing pre-treatment and post-treatment process. As a result of experiments, the factor effects on the adhesion between the cooper laminate and PSR is caused by all of the pre-treatment and post-treatment condition. A considerable change was observed depending on the amount of UV irradiation after thermal cure which is typical of printing post-treatment condition rather than pre-treatment condition.

• Journal of Surface Science and Engineering
• /
• v.32 no.3
• /
• pp.410-415
• /
• 1999

The adhesion strength of sputtered copper films to Inconel substrates has been studied using the scratch test. The effects of substrate treatments before deposition such as chemical or ion bombardment etching were investigated by means of a mean critical load derived from a Weibull-like statistical analysis. It was found that the mean critical load was very weak unless the amorphous layer produced by mechanical polishing on the substrate surface was eliminated. Chemical etching in a nitric-hydrochloric acid bath was shown to have practically no effect on the enhancement of the adhesion. In contrast, the addition in this bath of nickel and copper sulphates allowed removal of the amorphous layer and an increase in the values of the mean critical load. However, it was observed that excessive chemical etching could cancel out the mean critical load enhancement. The results obtained in the case of ion bombardment etching pretreatments could be far higher than those obtained with chemical etching. Moreover, for a sufficiently long period of ion bombardment etching, the adhesion strength was so high that it was impossible to observe evidence of an adhesion failure.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2003.05a
• /
• pp.31-32
• /
• 2003

In the Present study, the effect of galvannealing conditions on the phase distribution of the Zn-Fe intermetallic phases in the coating layer of the galvannealed steel sheets(GA) was investigated in an interstitial free steel and two kinds of high strength steels. The composition profiles of the coating layers were analyzed using AA and EDS analysis, and the distribution of the intermetallic phases was examined with the aids of X-ray diffraction. On the basis of the pole figure and OIM analyses, it was clarified that the preferred orientation of the $\zeta$ phase depended on the development of the $\gamma$-fibre texture in the substrate.

• Journal of Surface Science and Engineering
• /
• v.8 no.1
• /
• pp.15-23
• /
• 1975

Electrodeposition of metals form aqueous solutions (eg, electroplating ) is frequently accompanied, by the discharge of hydrogen ions(in acidic solutions) or water molecules ( in alkaline electrolytes). The atomic hydrogen produced thus may partly diffuse into the interior of the substrate and when this is absorbed by iron/steel substrate, it has detrimental effects on the mechanical properties of the steel, leading to ahydrogen embrittlement. Steels, particularly the high strength steels, are prone to hydrogen embrittlement. In view of the increasing applications of high strength steels in variousindustries, particularly in the aircraft manufacture, there has been renewed interest in the studiesonhydrogen embrittlement during electroplating of metals. In this review, the author summarizes the reports on hydrogen embrittlement during preplating of metals. In this review , the author sumamrizes the hydrogen embrittlement during electroplating of metals. In this review , the author summarizes the reports on hydrogen embrittlement during preplating operations and electroplating of metals like copper, nickel, tin, zinc ,cadimum and chromium. Finally, the effect of degassing by baking to deembrittle the plated high tensile steels and mechanism of hydrogen embrittlement are briefly indicated.

• Korean Journal of Chemical Engineering
• /
• v.35 no.12
• /
• pp.2474-2479
• /
• 2018

Plasma-enhanced atomic layer deposition (PEALD) is well-known for fabricating conformal and uniform films with a well-controlled thickness at the atomic level over any type of supporting substrate. We prepared nickel oxide (NiO) thin films via PEALD using bis(ethylcyclopentadienyl)-nickel ($Ni(EtCp)_2$) and $O_2$ plasma. To optimize the PEALD process, the effects of parameters such as the precursor pulsing time, purging time, $O_2$ plasma exposure time, and power were examined. The optimal PEALD process has a wide deposition-temperature range of $100-325^{\circ}C$ and a growth rate of $0.037{\pm}0.002nm$ per cycle. The NiO films deposited on a silicon substrate with a high aspect ratio exhibited excellent conformality and high linearity with respect to the number of PEALD cycles, without nucleation delay.

• Advances in nano research
• /
• v.4 no.1
• /
• pp.45-50
• /
• 2016

Data of Raman spectroscopy from graphene and few-layer graphene (FLG) irradiated by SEM electron beam in the range of energies 0.2 -30 keV are presented. The obvious effect of damaging the nanostructures by all used beam energies for specimens placed on insulator substrates ($SiO_2$) was revealed. At the same time, no signs of structural defects were observed in the cases when FLG have been arranged on metallic substrate. A new physical mechanism of under threshold energy defect production supposing possible formation of intensive electrical charged puddles on insulator substrate surface is suggested.

• Journal of the Korean Magnetics Society
• /
• v.5 no.5
• /
• pp.465-469
• /
• 1995

We have investigated the effects of deposition angle on structural and magnetic properties of e-beam evaporated ${(4-{\AA}\;Co/9.2-{\AA}\;Pt)}_{23}$ multilayer thin films prepared on tilted substrates. It was found that the [111] crystallographic orientations of the multilayer thin films were not aligned with colummar growth orientations and they were remained to be normal to the substrate planes even though the deposition angle was severely oblique up to $60^{\circ}$. The analysis of the torque curve reveal that the intrinsic anisotropy energy was monotonically decreased with the deposition angle but the easy axis orientation parallel to the substrate normal was not much influenced by deposition angle.