• 한국재료학회지
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• 제20권6호
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• pp.319-325
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• 2010

3-D IC integration enables the smallest form factor and highest performance due to the shortest and most plentiful interconnects between chips. Direct metal bonding has several advantages over the solder-based bonding, including lower electrical resistivity, better electromigration resistance and more reduced interconnect RC delay, while high process temperature is one of the major bottlenecks of metal direct bonding because it can negatively influence device reliability and manufacturing yield. We performed quantitative analyses of the interfacial properties of Al-Al bonds with varying process parameters, bonding temperature, bonding time, and bonding environment. A 4-point bending method was used to measure the interfacial adhesion energy. The quantitative interfacial adhesion energy measured by a 4-point bending test shows 1.33, 2.25, and $6.44\;J/m^2$ for 400, 450, and $500^{\circ}C$, respectively, in a $N_2$ atmosphere. Increasing the bonding time from 1 to 4 hrs enhanced the interfacial fracture toughness while the effects of forming gas were negligible, which were correlated to the bonding interface analysis results. XPS depth analysis results on the delaminated interfaces showed that the relative area fraction of aluminum oxide to the pure aluminum phase near the bonding surfaces match well the variations of interfacial adhesion energies with bonding process conditions.

• 한국공작기계학회논문집
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• 제18권1호
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• pp.116-121
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• 2009

Thermosonic flip chip bonding is an important technology for the electronic packaging due to its simplicity, cost effectiveness and clean and dry process. Mechanical properties of the horn and the shank, such as the natural frequency and the amplitude, have a great effect on the bonding capability of the transverse flip chip bonding system. In this research, two kinds of study are performed. The first is the new design of the clamp and the second is the effect of tolerance parameters to the performance of the system. The clamp with a bent shape is newly designed to hold the nodal point of the flip chip. The second is the effect of the design parameters on the vibration amplitude and planarity at the end of the shank. The variation of the tolerance parameters changes the amplitude and the frequency of the vibration of the shank. They, in turn, have an effect on the quantity of the plastic deformation of the gold ball bump, which determined the quality of the flip chip bonding. The tolerance parameters that give the great effect on the amplitude of the shank are determined using Taguchi's method. Error of set-up angle, the length and diameter of horn and error of the length of the shank are determined to be the parameters that have peat effect on the amplitude of the system.

• 마이크로전자및패키징학회지
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• 제27권4호
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• pp.1-10
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• 2020

웨어러블 소자를 구현하기 위한 칩-섬유 접합 기술을 중심으로 전자 섬유에 대한 기술 개발 동향을 소개한다. 전자 부품을 섬유에 접합하기 위해서는 먼저 전자 부품에 전원 공급 및 전기적 신호를 주고 받기 위한 회로를 섬유에 구성해야 하며, 회로의 해상도와 밀도에 따라 전도성 실을 이용하는 자수법 또는 전도성 페이스트 등을 이용한 프린트법을 통해 구현할 수 있다. 전자 부품과 섬유를 접합하기 위해서는 솔더링, ACF/NCA, 자수법, 크림핑 등의 방법을 이용하여 영구적으로 접합하거나 후크, 자석, 지퍼 등을 이용하여 탈부착이 가능하도록 접합하는 방법이 있으며, 접합 배선의 밀도 및 용도에 따라서 단독 또는 융합하여 사용한다. 접합 이후에는 방수 등 사용환경에서의 신뢰성을 확보하기 위해 encapsulation 작업을 수행해야 하며, 현재는 PDMS 등의 폴리머를 이용한 방법이 널리 쓰이고 있다.

• 한국산업융합학회 논문집
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• 제15권4호
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• pp.111-115
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• 2012

Ultrasonic meching technoloy has been developed over recent years for wire bonding.In this study, ultrasonic welding horn is analysed and designed with FEM, then manufactured based on it. The wire bonding mechine has been designed by conical horn model with very easy to come by and is readily accessible. The analysis is carried out by SoldEdge & Ansys software.

• 한국자동차공학회논문집
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• 제21권4호
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• pp.113-119
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• 2013

The transient liquid phase (TLP) bonding was used to fabricate autogenous joints in a magnesium alloy AZ31 with the aid of a pure Ni interlayer. A $13{\mu}m$ thick pure Ni foil was used in order to form a Mg-Ni eutectic liquid at the joint interface. The interface of reaction and composition profiles were investigated as a function of bonding time using a pressure of 0.16 MPa and a bonding temperature of $515^{\circ}C$. The quality of the joints produced was examined by metallurgical characterization and the joint microstructure developed across the diffusion bonds was related to changes in mechanical properties as a function of the bonding time.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 춘계학술대회 논문집
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• pp.250-253
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• 2001

Mechanical properties of gold bonding wire for VLSI packaging have been studied. The diameters of gold wires are about 20-30 micrometer and fracture loads are 8-20 gram force. The elastic modulus, yield strength, fracture strength and elongation properties have been evaluated by micro-tensile test method. This work discusses for an appropriate selection of micro-force testing system and grip design in mim testing. The best method to determine gauge length of wire and to measure tensile properties has been proposed. The mechanical properties such as strength and elastic modulus of current gold bonding wire are higher than pure those of gold wire.

• 한국군사과학기술학회지
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• 제8권3호
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• pp.51-55
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• 2005

In this paper, a near net shape technology using superplasticity and diffusion bonding characteristics was presented for application to various components of aircraft and missiles. Due to these special characteristics of some aerospace alloys, it is possible to produce complex components to shape very near final dimension with enhanced design freedom, reduced material usage, and overall saving of weight and cost. The high pressure vessel for a space launcher was fabricated with Ti-6Al-4V alloy by superplastic forming and diffusion bonding process and the failure characteristics are compared with conventionally fabricated vessel spin formed and TIG welded. The structural integrity of the superplastic forming and diffusion bonding process was successfully demonstrated.

• 대한기계학회논문집A
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• 제36권4호
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• pp.395-403
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• 2012

오늘날 접합시 열에 의한 재료 손상과 접착제(ACA, NCA) 이용으로 부품간의 정렬이 문제가 되고있다. 따라서, 본 논문은 FPCB 와 HPCB 금속(Au) PAD를 직접 접합하였다. 이때 박막인 재료에 손상을 입히는 열, 부품간의 정렬에 문제가 되는 접착제(ACA, NCA)를 사용하지 않고 상온에서 접합을 하였다. 접합시 초음파 혼을 이용하여 접합을 하였으며, 초음파혼은 40kHz이다. 공정 조건은 접합압력 0.60MPa, 접합시간 0.5, 1.0, 1.5, 2.0sec이다. 또한, 산업에서 요구하는 접합강도는 필강도 테스트 결과값으로 0.60Kgf 이상이며, 본 실험에서는 접합강도가 0.80MPa 이상이 나왔다. 이로서, 열에 의한 재료 손상과, 접 착제(ACA, NCA)에 의한 정렬 문제를 해결하였다. 그리고 산업산업에서 바로 적용하고 생산할 수 있는 FPCB, HPCB 시료 제작을 하였다.

• 반도체디스플레이기술학회지
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• 제20권4호
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• pp.171-176
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• 2021

Die-to-wafer (D2W) hybrid bonding in the multilayer semiconductor manufacturing process is one of wafer direct bonding, and various studies are being conducted around the world. A noteworthy point in the current die-to-wafer process is that a lot of voids occur on the bonding surface of the die during bonding. In this study, as a suggested method for removing voids generated during the D2W hybrid bonding process, a flexible mechanism for implementing convex for die bonding to be applied to the bond head is proposed. In addition, modeling of flexible mechanisms, analysis/design/control/evaluation of static/dynamics properties are performed. The proposed system was controlled by capacitive sensor (lion precision, CPL 290), piezo actuator (P-888,91), and dSpace. This flexure mechanism implemented a working range of 200 ㎛, resolution(3σ) of 7.276nm, Inposition(3σ) of 3.503nm, settling time(2%) of 500.133ms by applying a reverse bridge type mechanism and leaf spring guide, and at the same time realized a maximum step difference of 6 ㎛ between die edge and center. The results of this study are applied to the D2W hybrid bonding process and are expected to bring about an effect of increasing semiconductor yield through void removal. In addition, it is expected that it can be utilized as a system that meets the convex variable amount required for each device by adjusting the elongation amount of the piezo actuator coupled to the flexible mechanism in a precise unit.

• 소성∙가공
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• 제22권5호
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• pp.269-274
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• 2013

Experiments and numerical simulations of the incremental upsetting test were carried out to investigate void closure behavior and mechanical characteristic of a 1.5wt%C ultra-high carbon steel. The experimental results showed that the voids become quickly smaller as the reduction ratio increases. The simulation results confirmed this behavior and indicated that the voids were completely closed at a reduction ratio of about 40~45% during incremental upsetting. After the completion of the incremental upsetting tests, the process of diffusion bonding was employed to heal the closed voids in the deformed specimens. To check the appropriate temperature for diffusion bonding, deformed specimens were kept at 800, 900, 1000 and $1100^{\circ}C$ for an hour. In order to investigate the effect of holding time for diffusion bonding at $1100^{\circ}C$, specimens were kept at 10, 20, 30, 40, 50 and 60minutes in the furnace. A distinction between closed and healed voids was clearly established using microstructural observations. In addition, subsequent tensile tests demonstrated that complete healing of a closed void was achieved for diffusion bonding temperatures in the range $900{\sim}1100^{\circ}C$ with a holding time larger than 1 hour.