• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.9
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• pp.672-675
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• 1999

Si-to-Si electrostatic bonding was carried out by employing LSG interlayer instead of conventional Corning #7740 interlayer in order to improve bonding properties. The surface roughness and dielectric breakdown field of the LSG interlayers deposited on Si substrates were investigated. Also, the bonding interface, bonding strength and bonding mechanism were discussed for the electrostatically-bonded Si-Si wafer pairs having LSG interlayers.

• Journal of Welding and Joining
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• v.21 no.4
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• pp.69-74
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• 2003

The mechanical properties of STD11 Joints by using TLP (Transient Liquid Phase Diffusion) bonding method employing MBF-30 and MBF-80 insert metals were investigated with concerning to the microstructural change. TLP bonding of STD 11 was carried out at 1323∼1423K for 0.6ks∼3.6ks in vacuum. The microstructure and the element distribution of the interlayer between tool steels and insert metals showed specific feature with bonding conditions. It was found that the width of the interlayer increased at initial bonding stage. However, the width of interlayer showed nearly constant value during the isothermal solidification. After isothermal solidification was completed, the joint showed homogeneous element distribution and similar microstructure with base metal because of the grain boundary migration to the bonded interlayer. The bonding strength measured by a tensile test has been varied with the bonding conditions. The maximum joint strength, 760MPa, was obtained with the condition of 1423K for 1.2ks using MBF30 insert metal in this experiment.

• Journal of the Microelectronics and Packaging Society
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• v.7 no.1
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• pp.7-12
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• 2000

As an essential technology for the FED, VFD and PDP packaging having merits of no glass frit and no glass tube usage, two sodalime glass substrates were electrostatically-bonded in a vacuum environment, and the bond properties were compared with the case of bonding in atmosphere. The glass wafer pairs bonded in vacuum using a-Si interlayer had a relatively lower bond strength than the ones bonded in atmosphere under same bonding conditions (temperature and voltage). And the bond strength was increased in the case of oxygen ambient. Through the XPS and SIMS analyses fur the surface region of a-silicon and bulk glass, it might be concluded that the lower bonding strength was originated from the inactive silicon oxide growth occurred during the electrostatic bonding process due to oxygen deficiency in vacuum.

• Proceedings of the KWS Conference
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• 2004.05a
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• pp.48-50
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• 2004

TLP 접합 공정에서 모재와 삽입금속 사이에서의 확산을 통하여 액상 삽입금속은 고온에서 등온으로 유지 시 등온 응고된다. D.S.Duvall은 느린 가열시 매우 빠른 속도로 가열 시 보다 낮은 온도에서 dissolution이 완료되고 응고가 발생할 것으로 예상하였다. (중략)

• Journal of Mechanical Science and Technology
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• v.18 no.8
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• pp.1375-1387
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• 2004

A solution is given for the elastodynamic problem of a crack perpendicular to the graded interfacial zone in bonded materials under the action of anti plane shear impact. The interfacial zone is modeled as a nonhomogeneous interlayer with the power-law variations of its shear modulus and mass density between the two dissimilar, homogeneous half-planes. Laplace and Fourier integral transforms are employed to reduce the transient problem to the solution of a Cauchy-type singular integral equation in the Laplace transform domain. Via the numerical inversion of the Laplace transforms, the values of the dynamic stress intensity factors are obtained as a function of time. As a result, the influences of material and geometric parameters of the bonded media on the overshoot characteristics of the dynamic stress intensities are discussed. A comparison is also made with the corresponding elastostatic solutions, addressing the inertia effect on the dynamic load transfer to the crack tips for various combinations of the physical properties.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.10a
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• pp.248-253
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• 1998

Recently, the uses of Ceramic/metal bonded joints, resin/metal joints, adhesive joints, composite materials which are composed of dissimiliar materials have increased in various industry fields. Since the ceramic/metal bonded joints material is made at a high temperature, residual stress distributions due to differences in material properties were investigated by varying material parameters. The two dimensional finite element analysis was performed to study residual stress distribution in Si3N4/SM45C bonded joint with a copper interlayer between the silicon nitride(Si3N4) and the structural carbon steel(SM45C) and 4-point bending tests were carried out under room temperature. Fracture surface and crack propagation path were observed using scanning electron microscope and characteristics of its fracture was discussed.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.4
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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.

• Journal of Sensor Science and Technology
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• v.7 no.3
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• pp.211-217
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• 1998

Si and ITO-coated #7059 glass wafers were electrostatically bonded by employing #7740 interlayer. It was inferred that the thermionic- electrostatic migration of $Na^{+}$ ions in the #7740 interlayer played an important role in the bonding process through SIMS analysis. The temperature and voltage required for reliable electrostatic bonding were in the range of $180{\sim}200^{\circ}C$ and $50{\sim}70V_{dc}$(10min), respectively. The low temperature Si-ITO coated glass bonding can be effectively applied to the packaging of field emission devices.

• Korean Journal of Materials Research
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• v.9 no.10
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• pp.970-977
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• 1999

Effect of Mo interlayer on the relaxation of residual stress in AlN/Cu pint bonded by active-metal brazing method was investigated. The stress analyses by finite-element-method, the measurement of pint strength and the observation of fracture surface were carried out and their results were compared with each other. From the results of stress analysis it is confirmed that a Mo interlayer led to a shift of maximum stress concentration site from AlN/insert-metal interface$\rightarro$ insert-metal/Mo$\rightarro$Mo interlayer. Additionally, with increase of the Mo interlayer thickness the stress concentration with tensile component was separately built both at the interface of Cu/Mo and AlN/Mo. whereby the residual stress in the free surface of AlN close to the bonded interface was drastically reduced. The AlN/Mo/Cu pints with Mo interlayer thickness of above 400$\mu\textrm{m}$ showed the strengths higher than 200 MPa. upto max. 275 MPa, while the AlN/Cu pint only max. 52 MPa.

• Journal of Mechanical Science and Technology
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• v.17 no.2
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• pp.269-279
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• 2003

The anti-plane shear problem of bonded elastic materials containing a crack at an arbitrary angle to the graded interfacial zone is investigated in this paper The interfacial zone is modeled as a nonhomogeneous interlayer of finite thickness with the continuously varying shear modulus between the two dissimilar, homogeneous half-planes. Formulation of the crack problem is based upon the use of the Fourier integral transform method and the coordinate transformations of basic field variables. The resulting Cauchy-type singular integral equation is solved numerically to provide the values of mode 111 stress intensity factors. A comprehensive parametric study is then presented of the influence of crack obliquity on the stress intensity factors for different crack size and locations and for different material combinations, in conjunction with the material nonhomogeneity within the graded interfacial zone.