• 대한금속재료학회지
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• 제50권8호
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• pp.563-568
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• 2012

The wetting property and reflectivity of Sn-3.5Ag solder which was dip coated on a LED lead frame were investigated. The wettability of molten solder on Cu substrate was evaluated by the wetting balance tester, and surface tension was calculated from maximum withdrawal force and withdrawal time. Temperature of the molten solder in a bath was varied in the range of $250-290^{\circ}C$. With increasing temperature, the surface tension decreased a little. The reflectivity of Sn-3.5Ag coated on a substrate became a little lower than the highest current LED lead frame reflectivity.

• 대한치과의사협회지
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• 제41권1호통권404호
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• pp.35-41
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• 2003

Wettability of addition silicone impression material is very important property for making an accurate restoration. This study examined theimpression quality in clinical condition and the wettability of impression material. Three commercially available addition silicone impression material (Imprint; 3M, USA, Examix; GC, Japan, Perfect; Handae, Korea) were studied. A total of 90 putty/wash impressions of semi-dried premolars and wet molar teeth were examined for void production in impression body. The percentae of the sulcus reproduction ability of each material was calculated from the sulcus depths of cross-sectioned casts from the impressions with stereomicroscope. Three impression materials were used to produce die stone casts from vcid entrapment die. Voids in the stone casts were counted with the stereomicroscpe. From the experiment, the following results were obtained: 1. In direct observation, Imprint showed greatest numbers of void in impression body (P<.001).However, correlations were not found between sulcus reproduction and void production. 2. Sulcus reproduction ability of additional silicone impression material was diminished in order of Imprint, Examix, Perfect. The significant difference was found between Imprint and other material (P<.001). 3. In void entrapment laboratory test, void productions was diminished in order of Examix, Imprint, Perfect. All voids in casts were less in delayed poured cast than immediately poured cast. 4. Especially, the stone pouring time of Perfect impression material should be delayed.

• 한국안광학회지
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• 제10권2호
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• pp.119-126
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• 2005

2개사 칼라콘택트렌즈에 대한 물성적 특성을 평가 비교하였다. 제조된 인공누액을 사용하여 단백질 침착율과 습윤성, 주사전자현미경과 원자간력현미경을 이용하여 렌즈의 표면 거칠기를 관찰하였다. 결과는 다른 특성들은 일반 소프트콘택트렌즈와 비교해서 큰 차이를 보이지 않았으나 주사전자현미경적 관찰에서 건조시 심한 균열을 보였다. 원자간력현미경적 관찰에서 렌즈 표면요철은 발견되지 않아 표면거칠기는 일반 소프트콘택트렌즈와 차이가 없었다. 렌즈 앞면과 뒷면에 대한 염료 침착을 확인한 결과 염료는 렌즈내부에 존재함을 알 수 있었다.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2000년도 Proceedings of 5th International Joint Symposium on Microeletronics and Packaging
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• pp.74-79
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• 2000

In an attempt to estimate the wetting properties of wettable metal layers by wetting balance method, an analysis of wetting curves of the coating layer was performed. Based on the analysis, wetting properties of UBM-coated Si-plate were estimated by the new wettability indices. The wetting curves of the one and both sides-coated UBM layers have the similar shape and show the similar tendency to the temperature. So the wetting property estimation of one side coating is possible with wetting balance method. For UBM of Si-chip, Cr/Cu/Au UBM is better than Ti/Ni/Au in the point of wetting time. At general reflow temperature, the wettability of high melting point solders(Sn-Sb, Sn-Ag) is better than that of few melting point ones(Sn-Bi, Sn-In).The contact angle of the one side coated plate to the solder can be calculated from the farce balance equation by measuring the static state force and the tilt angle.

• 한국재료학회지
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• 제26권7호
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• pp.376-381
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• 2016

For the development of a low-melting point filler metal for brazing aluminum alloy, we analyzed change of melting point and wettability with addition of Sn into Al-20Cu-10Si filler metal. DSC results showed that the addition of 5 wt% Sn into the Al-20Cu-10Si filler metal caused its liquidus temperature to decrease by about 30 oC. In the wettability test, spread area of melted Al-Cu-Si-Sn alloy is increased through the addition of Sn from 1 to 5 wt%. For the measuring of the mechanical properties of the joint region, Al 3003 plate is brazed by Al-20Cu-10Si-5Sn filler metal and the mechanical property is measured by tensile test. The results showed that the tensile strength of the joint region is higher than the tensile strength of Al 3003. Thus, failure occurred in the Al 3003 plate.

• 한국전기전자재료학회논문지
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• 제20권12호
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• pp.1027-1033
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• 2007

In this research, the polishing pad for W CMP has been analyzed to understand stabilization of polishing performance. For stabilization of process, the polishing pad condition is one of important factors. The polishing pad plays a key role in polishing process, because it contact with reacted surface of wafer[1]. The physical property of pad surface is ruled by conditioning tool which makes roughness and profile of pad surface. Pad surface affects on polishing performance such as RR(Removal Rate) and uniformity in CMP. The stabilized pad surface has stable roughness. And its surface has high level of wettability which can increase the probability of abrasive adhesion on pad. The result of this research is that the reduction of break-in and dummy polishing process were achieved by artificial machining to make stable pad surface. In this research, urethane polishing pad which is named IC pad(Nitta-Haas Inc.) and has micro pore structure, is studied. Because, this type of pad is the most conventional type.

• 한국염색가공학회지
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• 제35권2호
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• pp.121-127
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• 2023

In this study, a comprehensive investigation was conducted on the morphological and property changes of laser-induced nanocarbon (LINC) as a function of laser process parameters. LINC was formed on the surfaces of polyimide films with different backbone structures under various process conditions, including laser power, scan speed, and resolution. Three different forms of LINC electrodes (i.e., continuous 3D porous graphene, wooly nanocarbon fibers, line cut) were formed depending on the laser power and scan speed. Furthermore, heteroatom doping induced from the chemical structure of the polyimide during laser patterning was found to be effective in modifying the electrical properties of LINC electrodes. The LINC surfaces exhibited different microstructures depending on the laser beam resolution under constant laser power and scan speed, allowing for controllable surface wettability. The correlation between the chemical structure of the polymer substrate, laser process parameters, and carbonized surface properties in this study is expected to be utilized as fundamental understanding for the manufacturing of next-generation carbon-based electronic devices.

• 한국결정성장학회지
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• 제25권3호
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• pp.105-110
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• 2015

근관 치료를 위해 사용되는 섬유 강화형 포스트를 광중합 레진과 유리섬유를 이용하여 제조하였다. 제조된 포스트는 유리 섬유의 밀도가 높아짐에 따라 기계적 특성이 향상됨을 확인 할 수 있었고 광중합 레진의 점도 조절 및 진공함침 공정을 통해 미세 기공을 효과적으로 제거 할 수 있었다. 유리섬유와 광중합 레진과의 계면 결합력을 향상시키기 위해 유리 섬유 표면을 실란 커플링제를 사용하여 표면처리를 하였으며, 유리섬유의 표면처리는 유리 섬유 표면에 레진의 젖음성을 향상시켜 레진과의 결합 특성을 향상시키고 포스트의 기계적 특성을 향상시킴을 확인할 수 있었다.

• 마이크로전자및패키징학회지
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• 제7권2호
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• pp.55-62
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• 2000

Si-wafer에 단면 코팅된 UBM(Under Bump Metallurgy)의 젖음성을 Sn-Pb 솔더에서 평가하기 위하여 wetting balance 법을 사용하였다. 단면 코팅된 UBM의 젖음곡선은 양면 코팅된 시편의 젖음 곡선과 비교할 때, 젖음곡선의 모양이 비슷하고 젖음곡선을 특징짓는 변수들의 온도에 대한 변화경향이 일치하였다. 단면 코팅된 금속층의 젖음성을 젖음곡선으로부터 정의한 새로운 젖음 지수 $F_{min}$, $F_{s}t_{s}$로 평가할 수 있었다. Au/Cu/Cr UBM은 젖음시간의 측면에서 Au/Ni/Ti UBM보다 젖음성이 우수하였다 Si-wafer에 단면 코팅된 UBM과 Sn-Pb 솔더의 접촉각을 $F_{s}$와 기울어짐각을 측정하고 메니스커스의 정적상태에서 힘의 평형으로부터 유도된 식을 이용하여 계산할 수 있었다.

• 한국염색가공학회지
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• 제27권1호
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• pp.18-26
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• 2015

para-aramid fibers were treated by atmosphere air plasma to improve the interfacial adhesion. The wettability of plasma-treated aramid fiber was observed by means of dynamic contact angle surface free energy measurement. Surface roughness were investigated with the help of scanning electron microscopy and atomic force microscopy. The tensile test of aramid fiber roving was carried out to determine the effect of plasma surface treatments on the mechanical properties of the fibers. A pull-out force test was carried out to observe the interfacial adhesion effect with matrix material. It was found that surface modification and a chemical component ratio of the aramid fibers improved wettability and adhesion characterization. After oxygen plasma, it was indicated that modified the surface roughness of aramid fiber increased mechanical interlocking between the fiber surface and vinylester resin. Consequently the oxygen plasma treatment is able to improve fiber-matrix adhesion through excited functional group and etching effect on fiber surface.