• Steel and Composite Structures
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• v.24 no.4
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• pp.391-397
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• 2017

With the increasing application of explosive composite structure in many engineering fields, its interface bonding state detection is more and more significant to avoid catastrophic accidents. However, this task still faces challenges due to the complexity of the bonding interface. In this paper, the concept of nonlinear output frequency response functions (NOFRFs) is introduced to detect the bonding state of explosive composite structure. The NOFRFs can describe the nonlinear characteristics of nonlinear vibrating system. Because of the presence of the bonding interface, explosive composite structure itself is a nonlinear system; when bonding interface of the structure is damaged, its dynamic characteristics show enhanced nonlinear characteristic. Therefore, the NOFRFs-based detection index is proposed as indicator to detect the bonding state of explosive composite pipes. The experimental results verify the effectiveness of the detection approach.

• Journal of the Semiconductor & Display Technology
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• v.10 no.2
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• pp.103-108
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• 2011

Ultrasonic welding is widely used in bonding of the same kind or dissimilar materials. The important variable of ultrasonic bonding is the bonding pressure, bonding time and applied amplitude energy. These variables have to be optimized in order to obtain the optimum bonding results. In this research, the important factor to optimal bonding between metal and glass were experimentally investigated by applying design of experiment.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.7
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• pp.28-35
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• 2010

In the display industry, COG bonding method is being applied to production of LCD panels that are used for mobile phones and monitors, and is one of the mounting methods optimized to compete with the trend of ultra small, ultra thin and low cost of display. In COG bonding process, electrical characteristics such as contact resistance, insulation property, etc and mechanical characteristics such as bonding strength, etc depend on properties of conductive particles and epoxy resin along with ACF materials used for COG by manufacturers. As the properties of such materials have close relation to optimization of bonding conditions such as temperature, pressure, time, etc in COG bonding process, it is requested to carry out an in-depth study on characteristics of COG bonding, based on which development of bonding process equipment shall be processed. In this study were analyzed the characteristics of COG bonding process, performed the analysis and reliability evaluation on electrical and mechanical characteristics of COG bonding using ACF to find optimum bonding conditions for ACF, and performed the experiment on bonding characteristics regarding fine pitch to understand the affection on finer pitch in COG bonding. It was found that it is difficult to find optimum conditions because it is more difficult to perform alignment as the pitch becomes finer, but only if alignment has been made, it becomes similar to optimum conditions in general COG bonding regardless of pitch intervals.

• Journal of the Semiconductor & Display Technology
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• v.4 no.4 s.13
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• pp.27-31
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• 2005

This article contains the development of FPC bonder that used for repair or trial product. Nowadays, in FPO module process (including PDP) accept the thermo-compress bonding method when attach FPC(Flexible Printed Circuit Board), TCP(Tape Carrier Package) and COF(Chip on the FPC) by ACF(Anisotropic Conductive Film). This system consists of ACF attachment part, pre-bonding part, main bonding part, loading / unloading part. This composition is a stand-alone system, not an in-line system. Hereafter, this composition should be developing into in-line system in all area of FPD industry.

• Journal of Welding and Joining
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• v.13 no.2
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• pp.132-138
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• 1995

Rene80 superalloy was liquid phase diffusion bonded by using boron(B) as an insert material, where B has high diffusivity and higher melting point as an insert material. Bonding procedure and bonding mechanism of Rene80/B/Rene80 joint were investigated. As results, liquid metal was produced by solid state reaction between base metal and insert material on bonding zone. The liquid metal was produced preferentially at the grain boundary. Except for production of liquid metal, other bonding procedure was nearly same as TLP(Transient Liquid Phase) bonding. Bonding time, however, was reduced compared to prior result of TLP bonding. By bonding S.4ks at l453K, Ren80/B/Rene80 joint was isothermally solidified and homogenized where thickness of insert material was 7.5.mu.m.

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.4
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• pp.30-37
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• 2015

iFLASH System is new structural floor system which consists of sandwich panels filled with nano-composite. The nano-composite has low specific gravity and high bonding strength with steel plates. The bonding strength is one of important factors for structural performance of iFLASH System and it can further be improved by surface preparation such as blast metal cleaning. However, using none blast steel plates is recommended since surface preparation generates additional fabrication time and cost. In this study, a bonding strength test and bending experiment were conducted to check feasibility of applying none blast steel plates to iFLASH System. Moreover, stress in bonding plane between steel plates and nano-composite was analytically evaluated by finite element method. Consequently, flexural capacity of the specimen was 11% higher than theoretically calibrated value and its flexural behavior was structurally efficient without defect of bonding.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.913-914
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• 2010

• Journal of Technologic Dentistry
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• v.29 no.2
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• pp.141-150
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• 2007

The purpose of this study was to ascertain the bonding durability of self-etching dentin bonding agents to dentin by means of shear bonding strength. Several acid-etching dentin bonding system (ESPE Z100) and self-etching dentin bonding systems (DEN-FIL, GRADIA DIRET) were used. The occlusion surface of human molars were ground flat to expose dentin and treated with the etch bonding system according to manufactures instruction and followed by composite resin application. After 24hours of storage at 37$^{\circ}C$, the shear bonding strength of the specimens was measured in a universal testing machine with a 1mm/min crosshead speed. An one-way analysis of variance and the scheffe test were performed to identify significant differences (p<0.05). The bonded interfacial surfaces and treated dentin surfaces were examined using a SEM. Through the analysis of shear bond strength data and micro-structures of dentin-resin interfaces, following results are obtained. In dentin group, the shear bond strength of DEN-FIL showed statistical superiority in comparison to the other groups and followed by ESPE Z100 and GRADIA DIRECT (p<0.05).

• Journal of the Microelectronics and Packaging Society
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• v.28 no.4
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• pp.109-114
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• 2021

We investigated the effects of atmospheric hydrogen plasma treatment on Cu-Cu direct bonding. Hydrogen plasma was effective in reducing the surface oxide layer of Cu thin film, which was confirmed by GIXRD analysis. It was observed that larger plasma input power and longer treatment time were effective in terms of reduction and surface roughness. The interfacial adhesion energy was measured by DCB test and it was observed to decrease as the bonding temperature decreased, resulting in bonding failure at bonding temperature of 200℃. In case of wet treatment, strong Cu-Cu bonding was observed above bonding temperature of 250℃.

• The Journal of the Convergence on Culture Technology
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• v.4 no.3
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• pp.209-212
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• 2018

Anisotropic conductive film(ACF) bonding is widely used for making fine interconnections between two different materials where soldering is not easily applicable. There are three constraints for the successful implementation of ACF bonding. A bonding contact should be pressed by a hot head with the right pressure and temperature for a pre-defined curing time. In this paper, a method for ACF bonding based on machine vision system is proposed and verified through some experiments. The system calculates the position and orientation of printed circuit boards(PCBs) on a bonding table and estimates the optimal hitting point where the hot head should be applied. Experimental results show that the proposed system achieves better adhesive strength by providing head flatness over contact surfaces.