• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1996년도 춘계학술발표회 초록집
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• pp.73-87
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• 1996

The outer-most electrons of metal atoms and the remining valence electrons of any molecular atoms make three dimensional crystallizing $\pi$-bondings. The electrons on the $\pi$-bonding orbital rotate clockwise or counter-clockwise and they then make electro-magnetic waves between atoms on the orbital because electron move between plus charged ions. The three dimensional crystallizing $\pi$-bonding orbitals are quantum-mechanically modeled by a cyclic Kronig-Penny Model and energy band structures are analyzed with their potential barrier thickness. The waves generated between plus charged ions are the particular $\pi$-far infrared rays, which have dual properties between material and electro-magnetic waves and can be measured not by modern electro-magnetic tester but biosensor such as finger's force tester. Because the $\pi$-rays can be modulated with electro-magnetic waves it can be applied for harmful electro-magnetic wave killers. Because the $\pi$-rays make new three dimensional crystallizing $\pi$-bonding orbitals in the material the food and drink can be transformed into a helpful physical constitutional property for human health. Distinction between crystalline and amorphous metals is possible because very strong crystalline $\pi$-bonding orbitals can not easily be transformed into another. The $\pi$-rays can also be applied for biofunctional diagnostics and therapy. Gravitational field is one of the electro-magnetic fields. And also magnetic field and gravitational force field make charge's movement. ($\times$ = q, : magnetic field, : force field, q: plus charge, : velocity field)

• 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.

• 한국세라믹학회지
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• 제20권1호
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• pp.70-78
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• 1983

This paper discusses the application of Si-Borosilicate glass sealing to a new sealing method which utilizes a large electrostatic field to pormote bound formation at relatively low temperature. Bonding mechanism and the effect of bonding time bonding temperature glass thickness and surface roughness on the bond strength were investigated. Application of a de voltage across bonded specimen gradually produced a layer of glass adjacent silicon which was depleted of mobile ions. As a consequence a n increasingly larger fraction of the applied voltage appeared across the depleted region and very large electric field resulted This field accompanyed by large electrostatic force acted as driving force the of strong bond. And stronger bond was formed with increasing bonding time and temperature. A low temperature preoxidation is advantageous for the Si surface having a rougher surface finish that 1 microinch.

• 대한치과보철학회지
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• 제30권1호
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• pp.73-83
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• 1992

Now composite resin restoration is clinically accepted in the repair of fractured PFM case, many mechanical surface treatment methods are performed to increase retentive force. The main purpose of this study was to compare the retentive force among the possible surface treatments and to insure the best method for the clinical application to the fractures porecelain and the exposed metal surface. To compare and to analyze the retentive force of repair resin, porcelain specimen were divided into 2 groups, etching group and non-etching group, and etching group were treated with 37% $H_3PO_4$, 1.23% APF, 10% HF and non-etching groups were treated with diamond bur, micro-sandblasasting. Also, metal specimens were divided by 2 groups : one was non-precious metal group which was treated with diamond bur, micro-sandblasting and tin plating and electrolytic etching, the other was precious metal group which was composed of micro-sandblasting treatment only and tin plating treatment with micro-sandblasting. Each specimen had been restored for 48 hours and the bond strength of each specimen was calculated with Universal testing machine. The results were as follows : 1. Porcelain specimen had higher bonding strength than metal specimen for the repair resin(P<0.01). 2. In porcelain specimen, 10% HF etching group had the highest bonding strength among etching and non-etching group. 3. Metal specimen treated with micro-sandblasting had highest bonding strength among the non-sandblasting had hightest bonding strength among the non-precious group, tin plating group had higher bonding strength than micro-sandblasting group between the precious metal groups. 4. Bonding strength of tin plating was increased in precious metal group only.

• 한국재료학회지
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• 제2권4호
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• pp.241-247
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• 1992

본 연구에서는 $Cu-Cu_2$O의 공정반응에 의한 구리와 알루미나의 직접접합에 대하여 연구 하였다. $1.5{\times}10^{-1}$torr, $1015^{\circ}C$에서 산화시킨 후 $10_{-3}$torr, 107$5^{\circ}C$에서 접합시킨 시편의 접합력과 계면특성을 인장시험, SEM, EDS 및 XRD를 통하여 분석하였다. 3분 산화시켜 접합하면 우수한 접합강도를 보이며 산화시간이 이보다 짧거나 길면 결합력은 저하하였다. 과단은 알루미나 공정조직 계면에서 발생하였으며 파단후 $Al_2O_3$표면에는 Cu쪽에서 빠져나간 $Cu_2$O nodule의 존재하였는 바 접합력은 $Cu_2$O-A$l_2O_3$계면보다는 $Cu-Cu_2$O계면에 좌우됨을 보여주고 있다. 접합력은 접합시간에 따라 완만한 증가를 보였으며 CuA$l_2O_4$및 $CuAlO_2$의 반응생성물이 접합중 형성되었다.

• 대한화학회지
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• 제59권2호
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• pp.132-135
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• 2015

Bonding force and stiffness in amine-linked single-molecule junctions for Ag electrodes were measured using a home-built conducting atomic force microscope under ambient conditions at room temperature. For comparison, Au electrodes were used to measure the rupture force and stiffness of the molecular junctions. The traces of the force along with the conductance showed a characteristic saw-tooth pattern owing to the breaking of the metal atomic contacts or the metal-molecule- metal junctions. We found the rupture force and stiffness for Ag are smaller than those for Au electrodes. Furthermore, we observed that the force required to break the amine-Ag bond in the conjugated molecule, 1,4-benzenediamine, is smaller than in 1,4-butanediamine which is fully saturated. These results consist with the previous theoretical calculations for the binding energies of the nitrogen bonded to Ag or Au atoms.

• 한국방사선학회논문지
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• 제8권7호
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• pp.371-376
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• 2014

CdTe 멀티에너지 X선 영상센서와 ROIC를 패키징 하기 위한 flip chip bump bonding, Au wire bonding 및 encapsulation 공정조건을 개발하였으며 성공적으로 모듈화 하였다. 최적 flip chip bonding 공정 조건은 접합온도 CdTe 센서 $150^{\circ}C$, ROIC $270^{\circ}C$, 접합압력 24.5N, 접합시간 30s일 때이다. ROIC에 형성된 SnAg bump의 bonding이 용이하도록 CdTe 센서에 비하여 상대적으로 높은 접합온도를 설정하였으며, CdTe센서가 실리콘 센서에 비하여 쉽게 파손되는 것을 고려하여 접합압력을 최소화하였다. 패키징 완료된 CdTe 멀티에너지 X선 모듈의 각각 픽셀들은 단락이나 합선 등의 전기적인 문제점이 없는 것을 X선 3D computed tomography를 통해 확인할 수 있었다. 또한 Flip chip bump bonding후 전단력은 $2.45kgf/mm^2$ 로 측정되었으며, 이는 기준치인 $2kgf/mm^2$ 이상으로 충분한 접합강도를 가짐을 확인하였다.

• 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.

• 한국분말재료학회지
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• 제28권1호
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• pp.1-6
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• 2021

Accurate and effective powder compaction analyses are performed for brittle materials such as graphite, utilized as a solid lubricant, by using the discrete element method (DEM). The reliability of the DEM analysis is confirmed by comparing the results of graphite powder compaction analyses using the DEM particle bonding contact model and particle non-bonding contact model with those from the powder compaction experiment under the same conditions. To improve the characteristics, the parameters influencing the compaction properties of the metal-graphite mixtures are explored. The compressibility increases as the size distribution of the graphite powder increases, where the shape of the graphite particles is uniform. The improved compaction characteristics of the metal-graphite (bonding model) mixtures are further verified by the stress transmission and compressive force distribution between the top and bottom punches. It is confirmed that the application of graphite (bonding model) powders resulted in improved stress transmission and compressive force distribution of 24% and 85%, respectively.

• 대한치과교정학회지
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• 제43권5호
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• pp.235-241
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• 2013

Objective: The purpose of this study was to investigate whether extension of the custom base is necessary for enhancement of bond strength, by comparing the debonding forces and residual adhesives of 3 different lingual bracket systems. Methods: A total of 42 extracted upper premolars were randomly divided into 3 groups of 14 each for bonding with brackets having (1) a conventional limited resin custom base; (2) an extended gold alloy custom base: Incognito${TM}$; and (3) an extended resin custom base: KommonBase${TM}$. The bonding area was measured by scanning the bracket bases with a 3-dimensional digital scanner. The debonding force was measured with an Instron universal testing machine, which applied an occlusogingival shear force. Results: The mean debonding forces were 60.83 N (standard deviation [SD] 10.12), 69.29 N (SD 9.59), and 104.35 N (SD17.84) for the limited resin custom base, extended gold alloy custom base, and extended resin custom base, respectively. The debonding force observed with the extended resin custom base was significantly different from that observed with the other bases. In addition, the adhesive remnant index was significantly higher with the extended gold alloy custom base. Conclusions: All 3 custom-base lingual brackets can withstand occlusal and orthodontic forces. We conclude that effective bonding of lingual brackets can be obtained without extension of the custom base.