Earticle

Purpose: To investigate shear bonding strength between dental zirconia ceramics with different surface treatment and metal bracket. Methods: Zirconia ceramics(LAVA, 3M ESPE, USA) were divided to 4 groups according to their surface treatment; no surface treatment(G1), sand blasting(G2), silane coating(G3), and sand blasting+silane coating(G4). Specimens were bonded to metal bracket using resin bond(TransbondTMXT, 3M Unitek, USA). Shear bond strength was measured using universal test machine(3366 INSTRON. U.S.A) with cross head speed of 1 mm/min. Microstructural investigation for fracture surface was performed after shear test. Results: Shear bonding strengths of single surface treatment groups (G2 and G3) were higher than no treatment group(G1). Combined Treatment Group (G4) showed the highest shear bond strength of 9.15 . Microstructural observation shows that higher shear bonding strength was obtained when debonding was occurred at metal bracket/resin interface rather than zirconia ceramic/resin interface. Conclusion: Surface treatment of zirconia is necessary to obtain higher bonding strength. Combined treatment can be more effective when surface the surfaces are kept clean and homogeneous.

본 연구는 학대아동의 부모-자녀 유대관계와 동적가족화의 반응특성 간의 상관관계를 알아봄으로써 학대아동에 대한 동적가족화의 유용성을 알아보고자 하는데 목적이 있다. 본 연구는 B광역시 초등학교 4～6학년 학대아동 132명을 대상으로 하였다. 연구결과는 다음과 같다. 첫째, 학대아동은 아버지보다 어머니를 더 애정적인 동시에 통제적인 것으로 지각하였다. 둘째, 부모상이 자아상보다 신체와 눈의 완성도가 낮고, 얼굴표정이 어둡고, 많이 생략된 것으로 나타났다. 부모상이 자아상보다 크고 특히 아버지상이 가장 크며 자아상과 부모상의 내부가 그려지지 않았거나 표정이 없는 것으로 나타났다. 셋째, 아동의 성별, 학년 및 형제순위, 가족수, 가족형태, 가정형편, 부모형태, 부부싸움횟수, 부모의 연령, 어머니의 종교와 직업유무 및 음주행태에 따라 동적가족화 반응특성에서 유의한 차이를 나타냈다. 넷째, 학대아동의 부모-자녀 유대관계와 동적가족화의 반응특성 간에 관련성이 있으며, 자아상-아버지상의 거리가 부모-자녀 유대관계를 가장 많이 반영하는 것으로 나타났다. 이상의 결과를 통해 학대아동이 그린 동적가족화는 부모-자녀 유대관계를 파악하는데 투사적 검사로서 활용할 수 있음을 알 수 있었다.

The purpose of this study is to see whether kinetic family drawing is a useful diagnostic tool in abused children. The subjects are 132 abused children. The results were as follows: 1. Abused children perceived that their mothers were more affectionate and overprotective than their fathers. 2. On the KFD of abused children, completion rates of body and eyes of parent-drawing were lower and omission rate was higher than self-drawing and face-expression is described darkly. The size of parent- drawing was bigger than self-drawing and size of father-drawing was biggest. There was little face-expression and inexpressive face. 3. The differences in the subject's reaction characteristics of KFD were affected by gender, order of birth and grade, number of family, family patterns, economic status, the count of quarrel between parent, father's age, and mother's age, religion, job and drink. 4. It was found that correlations between the characteristics of parental bonding and the reaction characteristics kinetic family drawing. The distance of between self-drawing and father-drawing mostly reflected characteristics of parental bonding. The results of this study indicate that the kinetic family drawing can be used a diagnostic tool in abused children.

The purpose of this study was designed to find characteristics of parental bonding relationships and characteristics by Kinetic Family Drawing of unmarried adolescent mothers. 116 unmarried adolescent mothers were studied using the test questionaire and drawing for analysis.The instruments of measurement were Kinetic Family Drawing environmental questionaire, parental bonding relationship Instrument(PBI). Frequency, Pearson's correlations, one-way-variance analysis were conducted for data analysis.The results were as follows;1. The general characteristics of unmarried adolescent mothers show that on completion of the body, of the face, size of figure-drawing, unmarried adolescent mothers were aware of intimately psychological affection for their mothers.2. On the family perception by Kinetic Family Drawing according to environmental variables. It has higher of self image, mother image, father image as being parents, form of the residence. 3. The characteristics of the Kinetic Family Drawing and parental bonding relationship by unmarried adolescent mothers show that they were aware of affection more mother than father and of control more father than mother.4. In relevance of the Kinetic Family Drawing and parental bonding relationship according to environmental variables, unmarried adolescent mothers have high completion rate of figure, eyes and faces of self-drawing. mother-drawing and father-drawing, face expression is described, figure drawing is described bigger when they have affection of the mother, exit their blood parents.In conclusion, unmarried adolescent mothers have influence of home environmental and of attitude parent's nurse.

Purpose: In this study, for the reasons of observing the changes when using bonding agent with Ni-Cr alloy and Co-Cr alloy and using VM13 and Vintage MP ceramic which have the disparity in coefficient of thermal expansion, it is carried out to evaluate the characteristics of the bonding agent through the analysis of the interface between metal and ceramic and the analysis of bond strength by variable. Methods: The surface treatment was performed on the two kinds of alloy(Ni-Cr alloy and Co-Cr alloy) specimens, which were sandblasted and were treated with bonder application. The metal-ceramic interfaces were analyzed with EPMA in order to ionic diffusion, and the shear test was performed. Results: As a result of observation of metal-ceramic interfacial properties, it was observed that Cr atoms were spread from the alloy body to the ceramic floor in the specimen of Group B. It was also seen that Cr, W atoms were spread from the alloy body to the ceramic floor in the specimen of Group S. In consequence of observing Shear bond strength, it was calculated that the specimen of BSV was 27.75( 11.21) , BSM was 27.02( 5.23) , BCV was 30.20( 5.99) , BCM was 27.94( 10.76) , SSV was 20.83( 2.58) , SSM was 23.98( 3.94) , SCV was 32.32( 4.68) , and SCM was 34.54( 10.63) . Conclusion: In the metal-ceramic interface of Bellabond plus sample group, diffusion of Cr atoms was incurred and diffusion of C Cr atoms and W atoms in the sample group of Starloy C was observed. Using bonding agent showed the higher bond strength than using the sand blasting treatment. In the Bellabond plus alloys, the specimen group with the use of binding materials showed higher shear bond strength, but didn’t show statistically significant differences (p>0.05). In the Starloy C alloys, the specimen group with the use of binding materials showed higher shear bond strength and statistically significant differences(p<0.05). In terms of VM13 ceramic, it was in the Bellabond plus alloys that the high shear bond strength was showed, but there’s no statistically significant differences (p>0.05). In terms of Vintage MP ceramic, it was in the Starloy C alloys that the high shear bond strength was showed and statistically significant differences(p<0.05). Metal-ceramic to fracture of the shear strength measurements and an analysis of all aspects of military usage fracture of the composite, respectively.

Purpose: The purpose of this study was to investigate the mechanical properties of polymer prosthetic and restorative materials for dental CAD/CAM using two test method; surface characteristics and shear bond strength. Methods: Commercialized CAD/CAM polymer blanks were investigated; One kinds of PMMA, and one PEKK blanks. A total of 20 PMMA and PEKK specimens were prepared, and each group was divided into 10 specimens. Average surface roughness was observed under surface profilometer. The contact angle was measured with a surface electrooptics. The bond strength was evaluated by a universal testing machine at a crosshead speed of 5mm/min. The data were statistically analyzed using independent t-test and Fisher’s exact test(P<0.05). Results: The PMMA and PEKK group showed a significant difference in the shear bond strength with the composite resin(P<0.05). The surface roughness of the PEKK group was higher than that of the PMMA group. The fracture mode were observed in PEKK groups with 50% showing adhesive remnant index score. Conclusion: PEEK is used as substructure material and composite veneering material is applied. PEKK resins will contribute to the development of successful products that will provide structural and aesthetic satisfaction.

This study evaluates the bonding strength characteristics of carbon fiber–foam sandwich structures for application in Wing-In-Ground(WIG) craft. Sandwich panel specimens were fabricated using low-temperature curing carbon fiber prepreg and PVC foam cores. The specimens were manufactured through a vacuum oven molding process to produce composite sandwich panels. To investigate the structural performance and interfacial bonding characteristics between the face sheet and the core, flexural tests and drum peel tests were conducted. The flexural tests were performed to evaluate the structural stiffness and failure behavior of the sandwich structure, while the drum peel tests were used to assess the adhesive bonding strength between the carbon fiber skin and the foam core. Based on the experimental results, the interfacial bonding behavior and failure characteristics of the carbon fiber–foam sandwich structures were analyzed. The results of this study are expected to provide fundamental data for the structural design and bonding performance evaluation of composite sandwich structures for WIG craft applications.

본 연구에서는 Sn-3.0Ag-0.5Cu 솔더를 이용한 자동차 전장부품의 다양한 chip을 선정하여, 장기신뢰성 평가 시험 방법 중 열충격 시험 전후 기계적 접합강도 특성을 검토하였다. 장기 신뢰성 평가 시험 후 기계적 접합강도의 값은 감소하는 결과를 나타내었다. 열충격 시험 후 각 시편의 기계적 접합강도가 평균 4.3 N이 감소하였으며, 열수명 시험 후 기계적 접합 강도의 감소는 평균 5.3N, 고온고습 시험 후 기계적 접합강도의 감소는 평균 3.8 N이었다. 시편의 최대 평균 감소율은 22.6 %로 C1 chip의 열수명 시험에서 나타났으며, 최소 평균 감소율은 3.5 %로 R1 chip의 고온고습 시험 후 나타났다. 상대적으로 시편이 큰 chip에서는 고온고습 시험이 작은 chip에서는 열수명 시험이 기계적 접합강도에 가장 크게 영향을 미치는 것으로 나타났다. 향후 보다 미세한 부품을 대상으로 공정조건 및 기계적 신뢰성 평가 기법을 확립하여야 할 것으로 사료된다.

In this study, the mechanical bonding strength were analyzed according to before and after long-term reliability evaluation test for various chips of automotive application component using Sn-3.0Ag-0.5Cu solder. In the after long-term reliability evaluation test, the mechanical bonding strengths tended to decrease. After thermal shock test, each specimen's mechanical bonding strengths decreased average 4.3N, in the case of after thermal life test, that of specimens decreased average 5.3N. After high-temperature & humidity test, mechanical bonding strengths decreased average 3.8N. The maximum average decreasing rate of specimens were 22.6% at thermal life test of Ci chip, and the minimum average decreasing rate of specimens were 3.5% at high-temperature & humidity test of R1 chip. In the case of large chip specimen, high-temperature & humidity test has a decisive effect on the mechanical bonding strengths. Inversely, in the small chip specimen, thermal life test has a decisive effect on the mechanical bonding strengths. For the reliability management, the process conditions and the mechanical reliability evaluation techniques should be established for the more fine component.

기존 연구논문에서 일정한 크기의 압력을 가할 수 있는 기계식 가압장비를 개발하여 보수단면에 시공되는 보 수재에 압력을 가할 경우 부착강도가 증가하는 효과를 확인할 수 있었다. 본 연구논문에서는 기계식 가압장비의 압력 을 0, 10, 30, 50 및 80kPa로 달리하여 재령 3 및 28일에서 공시체의 휨, 압축 및 부착강도와 가압판 변형을 측정한 결과를 분석하여 기계식 가압장비에 효과적인 압력을 선정하는 시험을 실시하였으며 시험결과 압력이 높을수록 강도 값은 증가하였으나 50kPa이상일 경우 가압판에 변형이 생기는 문제가 발생하였으며 이에 따라 강도값에 큰 차이가 없는 30kPa가 가장 효율적인 압력임을 알 수 있었다. 주성분이 실리카흄, 알루미나 시멘트 및 섬유를 서로 다르게 혼 합한 3종류의 보수재로 공시체를 제작한 후 건조 및 습윤 상태, 시공부위별 (천장부, 벽체부 및 바닥판) 그리고 가 압 유무에 따라 재령 3, 7, 14 및 28일에 부착강도를 측정한 결과 가압시 재령 3일 부착강도값이 비가압한 재령 7 및 14일 발현 강도값과 동등하거나 높아 공기단축이 필요로 하는 보수공사에 유리할 것으로 판단되었으며 가압시 신속 한 수분의 배출이 가능한 셀룰로오즈 섬유가 혼입된 보수재가 가압장비에 가장 효과적임을 알 수 있었다.

In the existing research paper, we developed Mechanical Pressurizing Equipment(MPE) that can apply a certain amount of pressure and found out about improving the bonding strength of repair materials constructed in the repair section, and if pressurized, the bonding strength could be increased. In this study, the pressure of Mechanical Pressurizing Equipment(MPE) was changed to 0, 10, 30, 50, and 80 kPa, and the test was conducted to select effective pressure by measuring the flexural, compressive, and bonding strength of the specimens and deformation of the pressure plate at the age of 3 and 28th days. As a result of the test, 30 kPa was the most efficient pressure for the MPE. After producing the specimen with three types of repair materials with different main components, the bonding strength was measured according to dry and wet conditions, construction site (ceiling, wall and floor), and whether or not pressurized, on the 3rd, 7th, 14th, and 28th, indicating that the repair materials mixed with cellulose fiber was most effective for the MPE.

In this study, to improve the bonding interfacial characteristics of active metal brazing (AMB) substrates, a Ag-Cu-Ti brazing filler metal (BFM) layer was formed on aluminum nitride (AlN) and silicon nitride (Si3N4) ceramics by nano sputtering. The AMB substrates were manufactured by brazing bonding. The measured peel strengths of the bonding interfaces of the AlN and Si3N4 ceramics were 2.35 kgf/mm and 4.26 kgf/mm, respectively. Fracture surface analysis revealed AlN crack initiation at the ceramic/BFM interface, which progressed into the ceramic interior. Silicon carbide (SiC) devices for a power module were bonded on the AMB substrates by Sn-3.0Ag-0.5Cu soldering and Ag sintering bonding. To compare the deterioration characteristics of the joint interfaces, a thermal shock test was conducted. Microstructural analysis after the thermal shock test showed that no defects occurred at the Si3N4/BFM interface, whereas delamination occurred at the AlN/BFM interface. Summarizing, in this study, the characteristics of AMB interfaces coated with a Ag-Cu-Ti BFM using the sputtering process were identified and the suitability of a SiC-based power module package was confirmed.

This paper describes anodic bonding characteristics of MCA to Si-wafer using evaporated Pyrex #7740 glass thin-films for MEMS applications. Pyrex #7740 glass thin-films with the same properties were deposited on MCA under optimum RF sputter conditions (Ar 100 %, input power $1\;W/cm^2$). After annealing at $450^{\circ}C$ for 1 hr, the anodic bonding of MCA to Si-wafer was successfully performed at 600 V, $400^{\circ}C$ in $110^{-6}$ Torr vacuum condition. Then, the MCA/Si bonded interface and fabricated Si diaphragm deflection characteristics were analyzed through the actuation and simulation test. It is possible to control with accurate deflection of Si diaphragm according to its geometries and its maximum non-linearity being 0.05-0.08 %FS. Moreover, any damages or separation of MCNSi bonded interfaces did not occur during actuation test. Therefore, it is expected that anodic bonding technology of MCNSi-wafers could be usefully applied for the fabrication process of high-performance piezoelectric MEMS devices.

The electronic structure and bonding in $Ti_2Pd$ and $Pd_2Ti$ alloys with and without hydrogen as an interstitial atom were studied by performing extended Huckel tight-binding band calculations. The hydrogen absorption near an octahedral site is found to be a favorable process in $Ti_2Pd$ rather than in $Pd_2Ti$. In metal hydrides, the metal-hydrogen bonding contribution is crucial to the stability of the system. The stronger interaction of hydrogen with Ti atoms in $Ti_2PdH_2$ than with Pd atoms in $Pd_2TiH_2$ is analyzed by perturbation theory.

졸-겔법에 의해 무기-유기 복합체를 합성하였으며, 복합체의 결합특성을 알아보기 위하여 DMTA(Dynamic Mechanical Thermal Analyzer)를 이용하여 유리전이 온돈(Tg)를 측정하였다. HCl 과 물의 양이 증가될수록 Tg는 고운으로 진행됨으로부터 복합화가 더 잘 일어남을 알 수 있었다. 그러나 반응시간에 따른 Tg의 변화는 관찰되지 않았다.

Inorganic/organic composite was synthesized by using sol-gel process, and the bonding characteristics of composite was investigated with glass transition temperature(Tg), measured by DMTA(Dynamic Mechanical Thermal Analyzer). It was found from shift of Tg to higher temperature that composite reaction was proceeded better with the amount of HCl and water. But Tg was not varied with reaction time.

This work studies the use of the CaO-Al2O3-SiO2-TiO2-ZnO (CASTZ)-based glass-ceramics, as a coating and bonding agentwas observed according to the change in Al2O3 substitution amount. Heat-treatment at 1000℃ is the standard procedure forbonding glass-ceramics with Al2O3 ceramics. The properties of the glass-ceramics and coatings are examined using X-raydiffraction, scanning electron microscopy, hardness measurements, and Raman analyses, to confirm the actual bondingmorphologies and thermal expansion coefficients. Titanite (CaTiSiO5) and willemite (Zn2SiO4) crystal phases are observeddepending on the amount of Al2O3 substitution, and as the substitution amount increases, anorthite (CaAlSi2O8) crystal phasesappear together. At this time, the microstructure densification and hardness change with variation in the heat-treatmenttemperature, indicating structural impact on glass, which is confirmed by Raman spectroscopy. A comparative analysis ofthe coefficients of thermal expansion between the substrate and glass-ceramic, along with actual bonding, reveals an increasein the bonding and wettability at higher Al2O3 substitution levels.

Diamond-like carbon (DLC) films were deposited on p-type (100) Si wafers using a plasma-enhanced chemical vapor deposition system and their structural bonding characteristics and mechanical properties were investigated as a function of the mixture ratio of methane-hydrogen gas and the bias voltage. It was found that the deposition rate increased with an increase in the flow rate of methane in the gas mixture and an increase in bias voltage. The sp3/sp2 ratio of carbon in the films and the hardness of the films increased with an increase in the flow rate of hydrogen in the gas mixture and an increase in the bias voltage.

Gold-coated silver wire was developed to alleviate the high cost of Au wire used in semiconductor packaging. Ball-bonding and stitch-bonding techniques were used to fabricate the dummy packaging material, comprising 97.3 % Ag, 97.3% Au-Coated Ag, and 99.99 %Au wires. The wire ball shear test (BST), the wire ball pull test (BPT), and the microstructural attributes of the ultrasonic bonding interfaces were compared with the initial properties, both be- fore and after the highly accelerated stress test (HAST), conducted at 130 ℃ and 85% relative humidity (RH). The initial bonding strength for all the wire variants was ?23~24 gf. Following the HAST, the bonding strength of the Ag wire, the Au-coated Ag wire, and the Au wire decreased by approximately 75 %, 47 %, and 17 %, respectively. The microstructure analysis revealed that cracks developed and propagated at the ends of the interface and that the Au-rich Au-Al intermetallic compound (IMC) inhibited the propagation of the crack at the ACA/Au wire interface. Additionally, it was discovered that the presence of the Ag-Au-Al IMC at the interface of the ACA wire reduced Kirkendall voids, which act as a barrier to Au-Al interdiffusion.

Copper wire bonding is an alternative interconnection technology that serves as a viable and cost saving alternative to gold wire bonding. In this paper, ultrasonic wedge bonding with $25{\mu}m$ copper wire on Au/Ni/Cu metallization of a PCB substrate was performed at ambient temperature. The central composite design of experiment (DOE) approach was applied to optimize the copper wire wedge bonding process parameters. After that, pull test of the wedge bond was performed to study the bond strength and to find the optimum bonding parameters. SEM was used to observe the cross section of the wedge bond. The pull test results show good performance of the wedge bond. Additionally, DOE results gave the optimized parameter for both the first bond and the second bond. Cross section analysis shows a continuous interconnection between the copper wire and Au/Ni/Cu metallization. The diffusion of Cu into the Au layer was also observed.

Carbon nanotube (CNT) cathodes were fabricated using nano-sized silver powders as a bonding material. The effects of powder size on the field emission properties for the CNT cathode were investigated The better emission properties of CNT cathodes using smaller particles are due to a low sintering temperature of the bonding materials.

In this study, the bonding characteristics of 100 μm diameter micro solder balls were comparatively analyzed according to the bonding process. Laser-assisted bonding (LAB) and vacuum reflow were applied, and an additional reflow process was conducted to simulate actual package assembly conditions. Accordingly, four bonding conditions were evaluated: LAB, LAB followed by reflow, vacuum reflow, and reflow followed by reflow. Cross-sectional microstructures were observed, and the thickness of intermetallic compounds (IMCs) was analyzed. In addition, shear strength measurements and fracture surface analyses were performed. The IMC thicknesses were 0.7, 2.3, 2.5, and 3.0 μm for LAB, LAB followed by reflow, vacuum reflow, and reflow followed by reflow, respectively. The shear strengths were 536.0, 520.3, 504.7, and 512.2 mN for the respective bonding conditions, showing no significant difference. Fracture analysis revealed that failure occurred within the solder matrix in all samples, indicating that the mechanical properties of the solder dominated rather than the interfacial strength. These results confirm that the LAB process is suitable for micro solder ball bonding applications and that it can effectively suppress IMC growth under multiple reflow conditions.