• 한국표면공학회지
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• 제54권5호
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• pp.207-212
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• 2021

The mechanical and electrical characteristics can be improved in 3D stacked IC technology which can accomplish the ultra-high integration by stacking more semiconductor chips within the limited package area through the Cu direct bonding method minimizing the performance degradation to the bonding surface to the inorganic compound or the oxide film etc. The surface was treated in a ultrasonic washer using a diamond abrasive to remove other component substances from the prepared cast plate substrate surface. FE-SEM was used to analyze the bonding characteristics of the bonded copper substrates, and the cross section of the bonded Cu conjugates at the sintering junction temperature of 100 ℃, 150 ℃, 200 ℃, 350 ℃ and the pressure of 2303 N/cm² and 3087 N/cm². At 2303 N/cm², the good bonding of copper substrate was confirmed at 350 ℃, and at the increased pressure of 3087 N/cm², the bonding condition of Cu was confirmed at low temperature junction temperature of 200 ℃. However, the recrystallization of Cu particles was observed due to increased pressure of 3087 N/cm² and diffusion of Cu atoms at high temperature of 350 ℃, which can lead to degradation in semiconductor manufacturing.

• 소성∙가공
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• 제31권4호
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• pp.179-185
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• 2022

The influence of post-roll bonding heat treatment conditions such as temperature and time on the variation in the diffusion layer, generated at the bonding interface and the subsequent mechanical properties of the roll-bonded Ti grade 1/Al1050/Ti grade 1 sheets, was systematically investigated. The intermetallic compound (IMC) phase generated by post heat treatment conditions adopted in this study was obviously indexed as monolithic TiAl₃. Whereas the thickness of IMC layer generated by annealing at 500 ℃ was approximately 100 nm scale, it drastically increased above 1.5 ㎛ when annealed at 600 ℃. Uniaxial tensile and peel tests were then performed to compare mechanical properties. As a result, the bonding strength drastically increased above 7.9 N/mm by annealing at 600 ℃, which implies that proper annealing condition was a prerequisite, to improving interface bonding strength as well as global elongation properties for Ti/Al/Ti 3-ply sheet.

• 센서학회지
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• 제9권2호
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• pp.134-140
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• 2000

Si기판 직접접합기술은 전자소자 및 MEMS에의 응용에 있어 대단히 매력적인 기술이다. 본 논문에서는 Si기판 직접접합에 있어서 HF 전처리 조건에 따른 초기접합에 관하여 서술한다. 접합된 시료들의 특성은 HF 농도, 인가하중과 같이 각각의 접합조건하에서 분석하였으며, 접합력은 인장강도측정법에 의해 평가하였다. 계면상의 결합성분과 표면의 거칠기는 FT-IR과 AFM을 사용하여 평가하였다. HF 전처리 후 Si기판 표면상의 Si-F결합은 DI water에 세정하는 동안 Si-OH로 재배열되며, 결과적으로 hydrophobic 기판은 Si-OH$\cdots$(HOH$\cdots$HOH$\cdots$HOH)$\cdots$OH-S의 수소결합되어 hydrophilic화된다. 초기접합력은 초기접합전의 HF 전처리 조건에 의존한다. (최소 : $2.4kgf/cm^2{\sim}$최대 : $14.9kgf/cm^2$)

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.282-285
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• 2006

This study is to examine bond strength of beam reinforced with GFRP rebar under 4-point bending test by adopting BRITISH STANDARD. The variables were made to have bonding length of 5times$(5d_b)$, 10times$(10d_b)$ and 15times$(15d_b)$ of the nominal diameter of GFRP rebar and were done to analyze the relationship between the bonding strength and the slip. In the result of the test, pull-out failure was dominant in the $5d_b$ and $10d_b$ specimen, both patterns of the pull-out failure and concrete splitting failure appeared in the $10d_b$. On the other hand, the $15d_b$ specimen showed only concrete splitting failure at the end of bonding length. Therefore, it was prove that available bonding length of the GFRP rebar under bending condition on static test is over $15d_b$ then farther research such as fatigue bending test, development of bonding model, FEM parameter study should be performed.

• 한국레이저가공학회지
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• 제11권3호
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• pp.10-15
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• 2008

This study is aimed to analyse the laser glass bonding process numerically. Due to the viscoelastic behaviour of glass, the extremely large deformation of the frit seal is resulted continuously over the transition temperature, so that the thermal boundary condition be changed in the entire calculation process. The commercial FEM algorithm is restrictively able to remesh the large geometrical boundary shape and to adapt the boundary conditions simultaneously. According to our manual adaptation of increasing the laser line intensity to 700 mW/mm, it is possible to estimate the thermal glass bonding process under the fracture stress in principle. But it should be studied further in the case of high laser line intensity.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1997년도 춘계학술대회논문집
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• pp.140-143
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• 1997

The present study is concerned with the hydrostatic extrusion process of copper-clad aluminium bar to investigate the basic flow characteristics. Considering the bonding mechanism of bi-metal contact surface as cold pressure welding, the normal pressure and the contact surface expansion are selected as process parameters governing the bonding condition. The critical pressure required for the bonding at the interface is obtained by solving a "local extrusion" using a slip line meyhod. A viscoplastic finite element method is used to analyze the steady state extrusion process. The boundary profile of bi-metal rod is predicted by tracking a particle path adjacent to interface surface. The variations of contact surface area and the normal pressure along the interface profile are predicted and compared to those by experiments.

• 한국자동차공학회논문집
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• 제5권2호
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• pp.87-93
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• 1997

The bonding strength evaluation of light weight materials for electrical vehicle applications has been performed through single lap joint tests in which the design parameters such as fillet, joint style, adherend, bonding overlap length,bonding thickness, and environmental condition(soaking time in $25^{\circ}C$ water) are considered. It is experimentally oberved that lap shear strength of joint increases for higher fillet height, longer overlap length, and thinner bonding layer thickness. Al-Al adherend combination shows much higher lap shear strength than AL-FRP and FRP-FRP adherend combinations. Riveting at adhesive bonded joint of AL-AL adherend combination makes lap shear strength decrease. Effect of soaking time on lap shear strength is negligible.

• 한국세라믹학회지
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• 제36권8호
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• pp.863-870
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• 1999

SOI(silicon on insulafor) was fabricated through the direct bonding using (100) Si wafer and 4$^{\circ}$off (100) Si wafer to investigate the stacking faults in silicon at the Si/SiO2 oxidized and bonded interface. The treatment time of wafer surface using MSC-1 solution was varied in order to observe the effect of cleaning on bonding characteristics. As the MSC-1 treating time increased surface hydrophilicity was saturated and surface microroughness increased. A comparison of surface hydrophilicity and microroughness with MSC-1 treating time indicates that optimum surface modified condition for time was immersed in MSC-1 for 2 min. The SOI structure directly bonded using (100) Si wafer and 4$^{\circ}$off (100) Si wafer at the room temperature were annealed at 110$0^{\circ}C$ for 30 min. Then the stacking faults at the bonding and oxidation interface were examined after the debonding. The results show that there were anomalies in the gettering of the stacking faults at the bonded region.

• 한국전기전자재료학회논문지
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• 제11권12호
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• pp.1079-1083
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• 1998

In this study, ultrasonic power of Aluminum wire bonder, bond time and bond force are investigated and valued in order to minimize failure of bonding pad lift. We also tried to control those 3 factors properly. We got the conclusion that if we turn down the ability of ultrasonic power or bond time, we can get a pad lift from a boundary between bond pad ad wire because pad metal and wire joining is unstable, but it is best condition when it ultrasonic power is 100∼130unit, bond time is 15∼20msec and bond force is 4∼6gf.

• 한국터널지하공간학회 논문집
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• 제11권1호
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• pp.71-83
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• 2009

숏크리트는 터널에서 적용되는 요요한 주지보재이다. 숏크리트의 품질평가는 터널의 안전한 시공과 효과적인 운영을 위한 핵심 요소이다. 숏크리트가 암반에 적절히 타설되었다 하더라도, 막장 및 벤치부에서의 발파, 수축, 지반의 변형 등으로 인해 숏크리트 균열발생 및 배면공동 등의 문제를 야기한다. 본 논문에서는 비파괴 시험인 충격 반항 기법(Impact-Echo) 및 지하레이다 탐사(GPR)를 이용하여 경임에 타설된 숏크리트 배면의 접착상태를 평가하고자 하였다. 기존의 수치해석 연구에 대한 검증과 더불어 현장 적용성에 대한 검토를 위해 실험적 연구를 수행하였다. 숏크리트의 접착상태는 완전 접착, 접착력 상실 및 공동 조건으로 구분할 수 있다. 실내 실대형 시험체에 이 세 가지 숏크리트 접착상태를 조사하였다. 충격반향시험으로부터 획득된 신호는 시간영역, 주파수 영역, 및 시간-주파수 영역에서 각각 분석되었다. 능동적 신호 처리 기법인 Short-Time Fourier Transform(STFT)을 이용하여 숏크리트 배면의 접착상태를 효과적으로 예측할 수 있었으며, 그 결과는 기존의 수치해석 연구로부터 획득한 신호특성과 잘 부합하였다. 숏크리트 배면의 접착상태가 불량할수록 다음과 같은 특징들을 나타낸다. 즉, 주파수 영역에서 자기스펙트럼밀도가 커지며, 기하학적 감쇠비는 감소하고, 시간-주파수 영역에서 윤곽선은 시간축에 평행한 형상을 나타내며, 숏크리트 두께가 얇을수록 그 공진시간이 길어진다. 또한 본 연구에서 제시한 상관계수를 이용하여 숏크리트의 접착상태를 정량적으로 평가할 수 있다. 본 연구 결과를 바탕으로 숏크리트의 접착상태를 평가할 수 있는 평가 기법 및 평가 기준을 제안하였다.