• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.1
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• pp.234-248
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• 1998

The purpose of this study was to compare the fracture and shear bonding strength of resin-modified glass ionomer cements with composite resin and conventional glass ionomer cement Three kinds of restorative materials including a composite resin (Z 100), a conventional glass ionomer cement(Fuji II), and resin- modified glass ionomer cements(Fuji II LC, Vitremer, Dyract and Compoglass) were investigated in this study. For measurement of fracture and shear bonding strength, disk samples of the materials were prepared and cylindrical samples of the materials were bonded the flat enamel and dentin surfaces according to manufactuer's instructions. All specimen were determinated by using an Instron testing machine with a crosshead speed of 1 mm/min. Then, each treated enamel and dentin surface was observed by SEM. The following results were obtained. 1. The bi-axial flexural strength of Z 100 was highest, and Fuji n LC, Vitremer, Dyract and Compoglass were significantly higher than Fuji n (P<0.05). 2. The shear bonding strength of Z 100 on the enamel and dentin surface was higher than other experimental groups except Fuji II LC(P<0.05). Fuji II LC was significantly higher than Fuji II (P<0.05), but in the case of Vitremer, Dyract and Compoglass were similar to Fuji II (P>0.05). 3. The shear bonding strength of Z 100 and Fuji II LC on the enamel surface were highly increased as compared with dentin surface (P<0.05), but in the case of Fuji II, Vitremer, Dyract and Compoglass were not different between enamel and dentin(P>0.05). 4. In the Z 100 and Fuji II LC, obvious etched enamel surface and exposed dentinal tubules according to remove of smear layer and smear plug were observed.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2000.10a
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• pp.39-45
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• 2000

A small camera module fabricated by including bare chip bonding methods is utilized to realize advanced mobile devices. One of the driving forces is the TOG (Tape On Glass) bonding method which reduces the packaging size of the image sensor clip. The TOG module is a new thinner and smaller image sensor module, using flip chip interconnection method with the ACP (Anisotropic Conductive Paste). The TOG production process was established by determining the optimum bonding conditions for both optical glass bonding and image sensor clip bonding lo the flexible PCB. The bonding conditions, including sufficient bonding margins, were studied. Another bonding method is the flip chip bonding method for DSP (Digital Signal Processor) chip. A new AC\ulcorner was developed to enable the short resin curing time of 10 sec. The bonding mechanism of the resin curing method was evaluated using FEM analysis. By using these flip chip bonding techniques, small camera module was realized.

• Restorative Dentistry and Endodontics
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• v.7 no.1
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• pp.77-83
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• 1981

The purpose of this study was to observe the bonding strength between tooth surface (enamel and dentin) and restorative filling materials which are two composite resins (Clearfil and Concise) and Glass ionomer cement, after etching with 50% phoshoric acid and 37% citric acid. To measure the bonding strength in enamel, the labial surface of upper anterior tooth was cut flatly with using carborundum disk and polished with sand paper disk, and to measure in dentin, the dentin surface was prepared by grinding upper part of posterior tooth horizontally. After washing the tooth surface with water and drying with air blast, the prepared tooth surface was etched. In glass ionomer cement, 50% phosphoric acid and 37% citric acid were used, in Clearfil 40% phosphoric acid was used and in Concise, 50% phosphoric acid and 37% citric acid were used as etchant for 1 minute. After the copper band which is 5 mm in diameter and 5 mm in height was fixed on the prepared surface and each filling material was inserted into the copper band, the hooking loop was inserted into filled material in the copper band before setting to make it easily that the load is applied on the specimen. After all specimens were immersed in water at $37^{\circ}C$ for 1 week, this specimen was placed on the load cell of tensile test apparatus, and specimen was pulled at the cross-head speed of 0.8 mm per minute. The following results were obtained 1) In glass ionomer cement, the bond strength obtained by 37% citric acid was higher than one obtained by 50% phosphoric acid in enamel and dentin surfaces. The bond strength obtained in non-etched surface was much less than one by etchants in enamel and dentin surface. 2) In Clearfil, the bond strength obtained by 40% phosphoric acid was 4 times more than one obtained by non etch ant. 3) In Concise, the bond strength obtained by 50% phosphoric acid was almost same as one obtained by 37% citric acid, and the bond strength obtained by non etch ant was much less than one obtained by etchants.

• Journal of the Korean Society of Safety
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• v.21 no.3 s.75
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• pp.73-80
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• 2006

Generally beam design depends on the yielding and maximum strength of each member varying with its section shape. Web plate of H-shape beam has not been substituted with glass plate, because it is known that its strength and heat properties are different and it is limited to substitute the existing steel web with glass element. Ceiling height of each room should be decreased with more than 60-80cm due to the beam. Differently from this condition, glass web beam has a good point to see through it and sunshine can be penetrate into the other size especially when it is installed as of outside wall. And also, it can be safer due to controlling room inside easier, if the strength is applicate. This study is to show some applicability after finding out the properties using the test. The test members with a size of $1,600{\times}200{\times}300{\times}9mm$ being SS41 rolled steel having THK 9mm flange while having 8,10mm and reinforced glass 12mm thickness is bonded with epoxy bond under the condition of temperature $28^{\circ}C$, humidity 50%, bonding power 24Mpa. It is show reinforced glass has 5 times of fracture stress more than the common glass but $50{\sim}150%$ difference between these 2 kinds of glass was shown. Reinforce glass did not support the original upper flange after fracture but the common glass did the upper flange after unloading. Generally reinforced glass is stronger than the common one but the common glass having a part of crack on it, compared with reinforced glass having the overall fracture could be more useful in case of needing ductility.

• Journal of the Korean Ceramic Society
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• v.32 no.10
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• pp.1203-1211
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• 1995

The tests of three point bending and vickers hardness have been carried out to investigate mechanical characteristics of bioceramics for artificial dental crowns. And color and color difference test has been performed to study chromaticity changes after sintering specimens composited with glass and leucite powders. In addition, thermal dilation test has been carried out to examine bonding relations between dental porcelain and metal frame (Ni-Cr alloy). The result of three point bending test showed a maximum strength of about 68 MPa. Thermal expansion coefficient changed from 8.3$\times$10-6/$^{\circ}C$ to 13.5$\times$10-6/$^{\circ}C$ with increasing leucite content (0~30wt.%) in glass matrix. Bonding between porcelain (25% leucite-75% glass) and Ni-Cr alloy was excellent.

• Analytical Science and Technology
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• v.5 no.3
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• pp.309-317
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• 1992

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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.923-924
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.1053-1054
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• 2009

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.874-877
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• 2001

SOI(Silicon-On-Insulator) technology is proposed as an alternative to bulk silicon for MEMS(Micro Electro Mechanical System) manufacturing. In this paper, we fabricated the SOI wafer with uniform active layer thickness by silicon direct bonding and mechanical polishing processes. Specially-designed electrostatic bonding system is introduced which is available for vacuum packaging and silicon-glass wafer bonding for SOG(Silicon On Glass) wafer. We demonstrated thermopile sensor and RF resonator using the SOI wafer, which has the merits of simple process and uniform membrane fabrication.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.12
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• pp.1639-1645
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• 2002

Micro engine that includes Micro scale combustor is fabricated. Design target was focused on the observation of combustion driven actuation in MEMS scale. Combustor design parameters are somewhat less than the size recommended by feasibility test. The engine structure is fabricated by isotropic etching of the photosensitive glass wafers. Electrode formed by electroplating of the Nickel. Photosensitive glass can be etched isotropically with almost vertical angle. Bonding and assembly of structured photosensitive glass wafer form the engine. Combustor size was determined to be 1 mm scale. Movable piston is engraved inside the wafer. Ignition was done by nickel spark plug which was electroplated with thickness of 40 ${\mu}{\textrm}{m}$. The wafers were bonded by epoxy that resists high temperature. In firing test due to the bonding method and design tolerance pressure buildup by reaction was not confirmed. But ignition, flame propagation and actuation of micro structure from the reaction was observed. From the result basement of design and fabrication technology was obtained.