• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.763-768
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• 2005

Bare-chip packaging becomes more popular along with the miniaturization of IT components. In this paper, we have studied flip-chip process, and developed automated bonding system. Among the several bonding method, NCP bonding is chosen and batch-type equipment is manufactured. The dual optics and vision system aligns the chip with the substrate. The bonding head equipped with temperature and force controllers bonds the chip. The system can be easily modified for other bonding methods such as ACF In bonding process, the bonding forte and temperature are known as the most dominant bonding parameters. A parametric study is performed for these two parameters. For the test sample, we used standard flip-chip test kit which consists of FR4 boards and dummy flip-chips. The bonding test was performed fur two types of flip-chips with different chip size and lead pitch. The bonding temperatures are chosen between $25^{\circ}C\;to\;300^{\circ}C$. The bonding forces are chosen between 5N and 300N. The bonding strength is checked using bonding force tester. After the bonding force test, the samples are examined by microscope to determine the failure mode. The relations between the bonding strength and the bonding parameters are analyzed and compared with bonding models. Finally, the most suitable bonding condition is suggested in terms of temperature and force.

• 한국전기전자재료학회논문지
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• 제22권8호
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• pp.625-631
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• 2009

In this thesis, lateral thermosonic bonding with ACFs was investigated as a process to make high reliability joints for FPD fabrication. Conditions for thermosonic and thermocompression bonding with ACFs were determined and used to make specimens in a driving test jig for testing of bond reliability by thermal shock. The results showed that thermosonic bonding temperature of $199\;^{\circ}C$ and bonding time of 1s produced bonds with good reliability. Additionally, thermosonic bonding temperature and time were reduced and thermal shock test results compared to this proposed curing condition. It is concluded that theromosonic bonding with ACFs can be effectively applied to reduce bonding temperature and time compared with that of thermocompression bonding.

• 비파괴검사학회지
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• 제26권5호
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• pp.343-352
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• 2006

본 논문에서는 금속 연소관, 단열 고무 그리고 내열 복합재로 구성된 연소관 조립체의 접착 체결 상태를 확인하기 위해 변형률, 음향방출 신호 그리고 초음파 시험자료를 이용한 비파괴 시험 방법이 제시되었다. 또한 내압 상태에서 연소관 조립체의 각 계면 접착 상태를 정량적으로 평가하기 위해 유한요소 해석이 수행되었다. 공압 시험 중 계측한 변형률 값과 음향방출 신호 상관관계 연구를 통해 연소관 조립체의 접착 건전성 평가가 가능했다. 그리고 연소관 조립체의 여러 접착 계면 중 첫 번째 계면인 연소관과 고무간의 접착은 초음파 방법으로 분류하였다. 이러한 연구를 통해 연소관 조립체의 모든 접착 계면은 1) 초기 완전 미접착, 2) 공압 시험 중 완전 접착 분리, 3) 공압 시험 중 부분 접착 분리, 4) 완전 접착 등 4가지 형태로 분류 및 검출되었다.

• Journal of Welding and Joining
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• 제30권6호
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• pp.113-119
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• 2012

Ultrasonic bonding is the novel packaging method for flip-chip with high yield and low-temperature bonding. The bonding module is a core part of the bonding machine, which can transfer the ultrasonic energy into the bonding spot. In this paper, we propose topology optimization technique which can make new design of boding modules due to the constraints on resonance frequency and mode shapes. The designed bonding module using topology optimization was fabricated in order to evaluate the bonding performance and reliable operation during the continuous bonding process. The actual production models based on the proposed design satisfied the target frequency range and ultrasonic power. The bonding test was performed using flip-chip with lead-free Sn-based bumps, the results confirmed that the bonding strength was sufficient with the designed bonding modules. Also the performance degradation of the bonding module was not observed after the 300-hour continuous process with bonding conditions.

• Journal of the Korean Wood Science and Technology
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• 제47권5호
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• pp.655-662
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• 2019

This study evaluated the multi-bonding performances of timbers as well as those of reinforcement and timber to obtain data for preparing guidelines regarding the use of timbers as large structural members. For the multi-bonding performances of timbers, four types of bonding surfaces were prepared according to the pith position. For the bonding performances of FRP (fiber-reinforced plastic)/steel plate and timber, a total of 11 types of specimens were produced for the selection of the appropriate adhesive. The bonding performances of the produced specimens were evaluated through a water soaking delamination test, a water boiling delamination test, and a block shear strength test. The test results showed that the bonding strength of the bonding surface according to the pith position was highest in the specimen for which the two sections with the pith at the center of the cross-section on timber and between the bonding surfaces (the tangential and radial sections were mixed) were bonded. Furthermore, the specimens for which the section (radial section) with the pith on the bonding surface of the timber was bonded showed a high delamination percentage. The results of the block shear strength test showed that the bonding section did not have a significant effect on the shear strength, and that the measured wood failure percentage was higher than the KS standard value. The PVAc adhesive showed the highest bonding strength between larix timber and GFRP (glass FRP). Furthermore, the epoxy and polyurethane adhesives showed good bonding strength for CFRP (carbon FRP) and structure steel, respectively.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.353-358
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• 2001

The cement concrete pavements are designed twenty years of performance life in Korea. At the present time, some expressways have been elapsed seventy percent of performance life which are detecting local failures. The most repair methods using to repair failures are partial depth repair and full section repair. These methods are most important bonding strength between rapid curing materials and substrate concrete pavements. This study was performed to evaluate bonding strength of the composites section made of rapid curing material and substrate concrete pavements. The pull-out tester was used to test bonding strength for the composites section made of each materials. In the results of the test, the bonding strength values of the epoxy mortar and acrylic mortar are higher than those of the other materials. The performance life of repaired section is affected by various factor. The bonding strength of bonded composites section may be affect the performance life, significantly.

• 한국재료학회지
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• 제5권2호
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• pp.191-196
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• 1995

비정질 PEEK 필름의 self-bonding강도는 접합시의 공정변수(시간, 온도, 그리고 압력)와 밀접한 관계가 있다. 본 연구에서는 이러한 공정변수의 효과를 규명하기 위하여 각기 다른 접합조건하에서 개발된 시편들의 self-bonding강도를 single lap-shear test를 통하여 측정된 각각의 전단 응력(shear strength)으로 나타내었다. 개발된 self-bonding강도는 접합온도가 증가함에 따라 증가하였으며, 접합시간의 1/4승에 일차함수적으로 비례증가하였다. 접합공정 중의 압력의 효과는 단지 초기 접합단계인 wetting에 기여하였을 뿐 self-bonding강도 자체에는 거의 영향을 미치지 않는 것으로 사려되었다. 결론적으로 비정질 PEEK 필름의 self-bonding현상은 현장에서의 실제 접합공정에서 어떠한 접착재료의 사용없이도 모재와 같은 강도를 개발하는데 무한한 가능성이 있는 것으로 판단되었다.

• Advances in materials Research
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• 제9권2호
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• pp.99-107
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• 2020

Reinforced aluminum alloy base composites have become increasingly popular for engineering applications, since they usually possess several desirable properties. Recently, Warm Accumulative Roll Bonding (WARB) process has been used as a new novel process to fabricate particle reinforced metal matrix composites. In the present study, TiO₂ particles are used as reinforcement in aluminum metal matrix composites fabricated through warm accumulative roll bonding process. Firstly, the raw aluminum alloy 1060 strips with TiO₂ as reinforcement particle were roll bonded to four accumulative rolling cycles by preheating for 5 min at 300℃before each cycle. The mechanical and bonding properties of composites have been studied versus different volume contents of TiO₂ particles by tensile test, peeling test and vickers micro-hardness test. Moreover, the fracture surface and peeling surface of samples after the tensile test and peeling test have been studied versus different amount of TiO₂ volume contents by scanning electron microscopy. The results indicated that the strength and the average vickers micro-hardness of composites improved by increasing the volume content of TiO₂ particles and the amount of their elongation and bonding strength decreased significantly.

• 마이크로전자및패키징학회지
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• 제27권3호
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• pp.55-60
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• 2020

최근 참단 반도체 패키징 기술은 고성능 SIP(system in packaging) 구조로 발전해 가고 있고, 이를 실현시키기 위해서 구리 대 구리 접합은 가장 핵심적인 기술로 대두되고 있다. 구리 대 구리 접합 기술은 아직 구리의 산화 특성과 고온 및 고압력 공정 조건, 등 해결해야 할 문제점들이 남아 있다. 본 연구에서는 아르곤과 질소를 이용한 2단계 플라즈마 공정을 이용한 저온 구리 접합 공정의 접합 계면 품질을 정량적 접합 강도 측정을 통하여 확인하였다. 2단계 플라즈마 공정은 구리 표면에 구리 질화막을 형성하여 저온 구리 접합을 가능하게 한다. 구리 접합 후 접합 강도 측정은 4점 굽힘 시험법과 전단 시험법으로 수행하였으며, 평균 접합 전단 강도는 30.40 MPa로 우수한 접합 강도를 보였다.

• 한국도로학회논문집
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• 제15권4호
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• pp.85-94
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• 2013

PURPOSES: The performance of tack coat, commonly used for layer interface bonding, is affected by application rate and curing time. In this study, bonding strength tests were performed according to the application rate and curing time of asphalt emulsion. Based on finding from this study, optimum application rates and curing times are proposed. METHODS: In order to investigate bonding characteristic of asphalt emulsion, tests were performed on both asphalt concrete pavement and portland concrete pavement. Also, asphalt emulsions were tested at the application rate of 0, 0.2, 0.4, 0.6, and $0.8{\ell}/m^2$ and at the curing time of 0, 0.5, 1, 2, and 24 hours. Pull-off test and shear bonding strength test, which commonly used for bonding strength measurement of asphalt emulsion, were adopted for this study. To assess field performance under different testing condition, asphalt emulsions were applied to in-service pavement. Throughout coefficient of determination analysis between material index properties from asphalt emulsion and mechanical response from bonding strength tests, performance correlativity was analyzed. RESULTS: Test results show that optimum application rate for asphalt overlay on asphalt concrete pavement (AOA) and asphalt overlay on concrete pavement (AOC) was $0.4{\sim}0.5{\ell}/m^2$ and $0.3{\sim}0.5{\ell}/m^2$, respectively. According to the curing time increment, tensile strength and shear strength of AOC were increased to 22~44% and 20~39%, respectively. AOA case also show strength increment in tensile strength (42%) and shear strength (9%). We tested the applicability of tack coat materials at the field sites, and our findings demonstrated that the bonding (for D and E) and rapid curing (for B, C, and D, E) performances were superior than others. Among material index properties, there was a high correlation between penetration ratio and bonding strength test result. CONCLUSIONS : Result show that interlayer bonding strength was affected by asphalt emulsion type, application rate and curing time. AOC required slightly higher application ($0.1{\ell}/m^2$) than AOA. Both AOA and AOC cases show higher strength at longer curing time. Up to 2hours of curing, rapid strength increments were observed, but strength increment ratio was decreased after 2hours of curing. From the observed correlation between penetration ratio and bonding strength, it is expected that penetration ratio can be used as one of important factors affecting bonding strength analysis.