• Journal of Welding and Joining
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• 제29권1호
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• pp.52-58
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• 2011

In this paper, the direct bonding process between FPCB and HPCB was studied. By using an ultrasonic horn which is mounted on the ultrasonic bonding machine, it is alternatively possible to bond the gold pads attached on the FPCB and HPCB at room temperature without an adhesive like ACA or NCA. The process condition for obtaining more bonding strength than 0.6 Kgf, which is commercially required, was carried out as 40 kHz of frequency, 0.6 MPa of bonding pressure and 2 second of bonding time. The peel off test was performed for evaluating bonding strength which results in more than 0.8 Kgf.

• 대한치과교정학회지
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• 제24권4호
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• pp.957-967
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• 1994

The purpose of this study was to evaluate the effects of different bases of ceramic brackets on shear bond strength and to observe failure patterns of bracket bondings. Lower bicuspid brackets whose bases designed for the macromechanical and silane treated chemical bonding those for silane treated chemical bonding, those for micromechanical bonding, and those for macromechanical bonding were tested as experimental groups, and foil mesh-backed metal brackets as a control group. All the brackets were bonded with $Mono-Lok\;2^{(TM)}$ on the labial surface of extracted human lower bicuspids after etching the enamel with $38\%$ phosphoric acid solution for 60 seconds. The shear bond strengths were measured on the universal test machine after 24 hours passed in the $37^{\circ}C$ water bath. The gathered data were evaluated and tested by ANOVA and Duncan's multiple range test, and those results were as follows. The shear bond strengths of brackets for macromechanical and chemical bonding, those for chemical bonding, and those for micromechanical bonding were not different (p>0.05), but showed statistically higher than those of metal bracket and those of ceramic bracket for micromechanical bonding(p<0.05). The shear bond strengths of ceramic bracket for micromechanical bonding showed statistically lower than those of metal bracket(p<0.05). The enamel fractures and/or ceramic bracket fractures were observed in the cases of higher bond strength than that of metal bracket. These results supported that silane treated base of ceramic bracket show higher shear bond strength than that of metal bracket, and suggested that micromechanical form of ceramic bracket bases show higher shear bond strength than that of macromechanical form.

• 한국재료학회지
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• 제18권4호
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• pp.204-210
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• 2008

$1.5\;{\mu}m$-thick copper films deposited on silicon wafers were successfully bonded at $415^{\circ}C$/25 kN for 40 minutes in a thermo-compression bonding method that did not involve a pre-cleaning or pre-annealing process. The original copper bonding interface disappeared and showed a homogeneous microstructure with few voids at the original bonding interface. Quantitative interfacial adhesion energies were greater than $10.4\;J/m^2$ as measured via a four-point bending test. Post-bonding annealing at a temperature that was less than $300^{\circ}C$ had only a slight effect on the bonding energy, whereas an oxygen environment significantly deteriorated the bonding energy over $400^{\circ}C$. This was most likely due to the fast growth of brittle interfacial oxides. Therefore, the annealing environment and temperature conditions greatly affect the interfacial bonding energy and reliability in Cu-Cu bonded wafer stacks.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 춘계학술발표대회 개요집
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• pp.285-287
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• 2002

This study is investigated in variations of micro-structures and mechanical properties of Ti/SUS321L joint with bonding temperature and time using brazing method. According to increasing bonding temperature and time, it was observed the thickness of their reaction layer increased. In tensile test, it was examined that the tensile strength had maximum value at the bonding time of 5min and decreased after bonding time over 5min because of increasing their oxides and intermetallic compounds.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1501_1502
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• 2009

Plasma treatment time was optimized to maximize the bonding strength between silicon and quartz. Bonding strength between the silicon and quartz is related to a surface energy which can be calculated by contact angle measurement. It was found that optimized time to get maximized surface energy was 15 sec. Silicon and quartz wafers were treated with $O_2$ plasma under different time splits and then bonded together. Bonding strength of the bonded wafers was measured by shear test. It was verified that the highest bonding strength was obtained when the silicon and quartz wafers were treated for 15 seconds. The maximum bonding strength exceeded the fracture strength of silicon.

• 마이크로전자및패키징학회지
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• 제18권2호
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• pp.63-67
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• 2011

본 연구에서는 interlayer로 Sn을 사용하여 경성 인쇄 회로 기판(Rigid printed circuit board, RPCB)과 연성 인쇄 회로 기판(Flexible printed circuit board, FPCB) 간의 열압착 접합(Thermo-compression bonding) 조건을 최적화하는 연구를 진행하였다. 접합에 앞서 FPCB를 다양한 온도와 시간조건 하에서 Sn이 용융된 솔더 배스 안에서 침지(Dipping) 공정을 수행하였고, 열압착법을 이용하여 FPCB와 RPCB의 접합을 수행하였다. FPCB/RPCB 접합부의 접합 강도를 $90^{\circ}$ 필 테스트(Peel test)를 이용하여 측정하였다. 그 결과 $270^{\circ}C$, 1s의 침지 조건에서 FPCB의 polyimide(PI)와 Cu 전극 계면에서 파단되고, 이때, 최대 박리 강도를 얻었다. FPCB와 RPCB의 열압착 접합시 주요 변수로는 압력, 온도, 시간이 있으며, 특히 온도의 증가에 따라 접합 강도가 크게 증가하였다. 접합부 계면 관찰 결과, 접합 온도와 시간이 증가함에 따라 접합 면적이 증가하였으며, 이로 인해 접합 강도가 증가하는 것으로 사료된다. 필 테스트 과정에서 나타나는 F-x(Forcedisplacement) 곡선을 토대로 산출한 파괴 에너지와 접합 강도는 $280^{\circ}C$, 10s의 접합 조건에서 가장 높게 나타났으며, 이 조건이 최적 접합 조건으로 도출되었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.88-91
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• 2004

It is generally known that the bonding strength of RC(Reinforced Concrete) flexural members strengthened by fiber sheet composites are sufficient and the bonding failure does not occur until the sheet failed. However, many researchers have been reported that, before the failure of the sheet, the bonding failure happens even though the bonding length is sufficient. This study was carried out to evaluate the effectiveness of shear key and U strip on flexural behavior of reinforced concrete beam structures. The ply number of CFS(Carbon Fiber Sheet), location of shear key, and existence or not of U strip were selected as the main test variables. Test results show that the behavior of a beam of which shear key is located in the nearby. of support and U strip is not existent, and having CFS of 1 ply is mostly improved.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1998년도 추계학술대회 논문집
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• pp.273-278
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• 1998

In this paper, basic micro-mechanical properties of unidirectional CFRP composite shell such as bonding strength, fiber volume fraction and void fraction are measured and tensile strength test is performed with a fixture. And then fracture surfaces are observed by SEM. In case of basic micro-mechanical properties, bonding strength is reduce with decreasing of radius of each ply in a shell for the effect of residual stress, fiber volume fraction is smaller than plate, and void fraction is vise versa. For these reason, tensile strength of shell is smaller than plate fabricated with same prepreg. For failure mode shell has many splitted part along its length, and it is assumed that this phenomenon is caused by the difference of bonding strength for residual stress.

• 한국산업융합학회 논문집
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• 제9권3호
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• pp.183-190
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• 2006

Generally, application of steel pile as deep foundation member needs specials requirement for the connection method between steel pipe and concrete footing. To investigate real compressive behavior of connection member between steel pipe pile and concrete footing, three specimens were tested with carefully designed experimental system. Main test variable is the connection method between steel pipe pile and concrete footing. The bolted bonding method and hook bonding method was considered as the connection method in this study. From the test results gained from experiment, it was conformed that two types of connection method have the almost same compressive resistance capacity. Therefore, we can conclude that these two connection methods can be used as the strengthening method to verify the compressive composite action of concrete and steel pipe pile.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2004년도 추계 기술심포지움 초록집
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• pp.11-11
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• 2004