• Proceedings of the KWS Conference
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• 2010.05a
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• pp.78-78
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• 2010

모바일 정보통신기기를 중심으로 패키지의 초소형화, 고집적화를 위해 플립칩 공법의 적용이 증가되고 있고 있으며 접속피치의 미세화에 따라 솔더 및 언더필을 사용하는 C4 공법보다 ACA(Anisotropic Conductive Adhesive), NCA (Non-conductive Adhesive) 등의 접착제를 이용하는 칩본딩 공법에 대한 요구가 증가하고 있다. 특히, NCA 공법의 경우 산업 현장의 대량생산에 대응하기 위해서는 접착제의 속경화 특성이 요구되어 진다. 일반적으로 접착제의 경화거동은 DSC(Differential Scanning Calorimeter)를 사용해 확인하지만, 수초 이내에 경화되는 접착제의 경우는 적용되기 어렵다. 본 연구에서는 이러한 전자패키지용 접착제의 속경화 거동을 효과적으로 평가할 수 있는 방법을 조사 하였다. 실험에서 사용된 접착제는 에폭시계 레진 기반에 이미다졸계 경화제를 사용한 기본적인 포뮬레이션을 사용하였고, 경화시간은 160^{\circ}C에서 1분 이내에 경화되는 특성을 가지고 있다. 경화 거동을 확인하기 위해서 isothermal DSC와 DEA(Dielectric Analysis)의 두가지 방법을 사용해 비교하였다. 두 실험 방법 모두 $160^{\circ}C$를 유지하며 경화 거동을 확인하였고, DoC(Degree of Cure)의 측정오차를 비교 분석하였다. DEA는 이온 모빌리티 변화에 따른 유전손실율을 측정하는 방법으로 80~90% 이후의 경화도는 측정되지 않았지만, 수초 이내에 경화되는 속경화 특성을 평가하기에 적합한 것으로 확인되었다.

• Journal of the Korea Society of Computer and Information
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• v.6 no.3
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• pp.131-136
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• 2001

Men's dress shoe was made from Steer-finished leather manufactured by this study. Men's dress shoe applied by the cementing method in KS G 3116 and used by the chloroprene adhesive has been evaluated. For the qualify test of adhesive for Oxford using chloroprene adhesive, duration for environmental exposure was tested. Also, the quality test result of chloroprene adhesive, which had been applied to men's dress shoe as well as ladies' dress shoe, was better than expected. In case of adhesion-strength measurement. the KS G 3116 method of peel strength at the end of toe was found to be resonable compared to our measurement method through toe to heel seat on feather edge.

• Restorative Dentistry and Endodontics
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• v.34 no.5
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• pp.397-405
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• 2009

This study compared the effect of an activator, intermediate bonding resin and low-viscosity flowable resin on the microtensile bond strength of a self-curing composite resin used with two-step total etching adhesives. Twenty extracted permanent molars were used. The teeth were assigned randomly to nine groups (n=10) according to the adhesive system and application of additional methods (activator, intermediate adhesive, flowable resin). The bonding agents and additional applications of each group were applied to the dentin surfaces. Self-curing composite resin buildups were made for each tooth to form a core, 5mm in height. The restored teeth were then stored in distilled water at room temperature for 24h before sectioning. The microtensile bond strength of all specimens was examined. The data was analyzed statistically by one-way ANOVA and a Scheffe's test. The application of an intermediate bonding resin (Optibond FL adhesive) and low-viscosity flowable resin (Tetric N-flow) produced higher bond strength than that with the activator in all groups. Regardless of the method selected, Optibond solo plus produced the lowest ${\mu}TBS$ to dentin. The failure modes of the tested dentin bonding agents were mostly adhesive failure but there were some cases showed cohesive failure in the resin.

• Restorative Dentistry and Endodontics
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• v.35 no.5
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• pp.321-334
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• 2010

Objectives: The purpose of this study is to evaluate bonding efficacy by means of measuring the effect of remained solvent on Degree of conversion(DC) and ${\mu}TBS$ and FE-SEM examination. Materials and Methods: Two 2-step total etching adhesives and two single-step self etching adhesives were used in this study. First, volume weight loss of 4 dentin adhesives were measured using weighting machine in process of time in normal conditions and calculate degree of evaporation (DE). Reaction/reference intensity ratio were measured using micro-Raman spectroscopy and calculate DC according to DE. Then 2 experimental groups were prepared according to air-drying methods (under, over) and control group was prepared to manufacturer's instruction. Total 12 groups were evaluated by means of micro tensile bond strength and FE-SEM examination. Results: Degree of evaporation (DE) was increased as time elapsed but different features were observed according to the kind of solvents. Acetone based adhesive showed higher DE than ethanol and butanol based adhesive. Degree of conversion (DC) was increased according to DE except for $S^3$ bond. In ${\mu}TBS$ evaluation, bond strength was increased by additional air-drying. Large gaps and droplets were observed in acetone based adhesives by FE-SEM pictures. Conclusions: Additional air-drying is recommended for single-step self etching adhesive but careful consideration is required for 2-step total etching adhesive because of oxygen inhibition layer. Evaporation method is carefully chose and applied according to the solvent type.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.56.2-56.2
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• 2011

최근 철강, 알루미늄, 이종재료의 접합 등 용접이 어려운 부분에 구조용 접착제의 적용이 증가하고 있는 추세이다. 이를 위해 변성 에폭시레진을 활용한 고접합 강도, 고인성의 구조용 접착제가 연구되어 지고 있다. 피착제의 표면처리는 접합부의 접합강도를 향상시키는 방법으로 알려져 있으나 최근의 구조용 접착제는 표면 전처리 없이도 우수한 접착 특성을 보이는 것으로 기대되고 있다. 본 연구에서는 변성레진에 대해서 각종 표면처리가 접합부 특성에 미치는 영향을 조사하였다. 피착제로는 자동차용 냉연강판인 SPRC440을 사용하였고, 전처리로는 무처리 상태, SiC연마지를 이용한 연마, 아르곤 및 산소가스를 이용한 마이크로웨이브 플라즈마 표면처리, 산세 등의 표면처리를 실시하였다. 에폭시 접착제는 변성 에폭시 레진과 경화제 및 촉매제를 이용하여 직접 포뮬레이션하였다. 단일 겹치기 전단강도 시험과 T-Peel 시험은 각각 ASTM D 1002 규격에 따라 준비하였으며 인장 시험 후 파면은 SEM으로 관찰하였다.

• Restorative Dentistry and Endodontics
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• v.32 no.3
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• pp.198-207
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• 2007

The purpose of this study was to investigate the effect of calcium hydroxide on dentin bonding strength of various dentin bonding systems as a function of time in composite resin restoration. Dentin adhesives used in this study were Scotchbond Multipurpose, Single Bond, SE Bond and Prompt L-Pop. Flat dentin surfaces adjacent to pulp chamber were created, then $Ca(OH)_2$ and saline were mixed and applied on dentin surface of experimental group, then IRM was used to cover the mixture on dentin surface and the specimens were stored at $36.5^{\circ}C$ for experiment period (7 days, 30 days). After removing IRM and $Ca(OH)_2$, each dentin adhesives were treated on dentin surfaces. Composite resin (Z-250, 3M) was placed with S mm height and was light-cured for 20 seconds. After stored in distilled water for 24 hours, each dentin-composite bonded spicemen was embedded in epoxy resin and sectioned into $1.0\times1.0mm^2$ cross section composite-dentin beams. Specimen was mounted on zig of Universal testing machine and ${\mu}TBS$ test was performed. SEM analysis was performed to examine the fractured surfaces. The results suggested that applying calcium hydroxide did not show significant difference in dentin bonding strength.

• Restorative Dentistry and Endodontics
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• v.36 no.3
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• pp.203-210
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• 2011

Objectives: The purpose of this study was to evaluate the effect of various application methods of one-step self-etch adhesives to microtensile resin-dentin bond strength. Materials and Methods: Thirty-six extracted human molars were used. The teeth were assigned randomly to twelve groups (n = 15), according to the three different adhesive systems (Clearfil Tri-S Bond, Adper Prompt L-Pop, G-Bond) and application methods. The adhesive systems were applied on the dentin as follows: 1) The single coating, 2) The double coating, 3) Manual agitation, 4) Ultrasonic agitation. Following the adhesive application, light-cure composite resin was constructed. The restored teeth were stored in distilled water at room temperature for 24 hours, and prepared 15 specimens per groups. Then microtensile bond strength was measured and the failure mode was examined. Results: Manual agitation and ultrasonic agitation of adhesive significantly increased the microtensile bond strength than single coating and double coating did. Double coating of adhesive significantly increased the microtensile bond strength than single coating did and there was no significant difference between the manual agitation and ultrasonic agitation group. There was significant difference in microtensile bonding strength among all adhesives and Clearfil Tri-S Bond showed the highest bond strength. Conclusions: In one-step self-etching adhesives, there was significant difference according to application methods and type of adhesives. No matter of the material, the manual or ultrasonic agitation of the adhesive showed significantly higher microtensile bond strength.

• Composites Research
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• v.22 no.2
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• pp.14-17
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• 2009

Adhesive joints are widely used for structural joining applications in various fields and environmental conditions. Polyurethane adhesive is using for LNG carrier with cryogenic temperature condition. In industrial application of polyurethane adhesive, void of adhesive layer is often discussed regarding its effects on bonding properties. In present study, artificial void were prepared on Polyurethane adhesive layer with various size and location. The single lap shear test was carried out by using prepared specimens under $-170^{\circ}C$. As a result, it was confirm that the void of adhesive layer didn't affect the adhesion properties independent of their size and location.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.2
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• pp.165-172
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• 2019

The purpose of this study was to evaluate the effect of application time and phosphoric acid etching of 8th generation adhesives containing functional monomer on adhesive performance in primary teeth. 80 extracted non-carious human primary teeth were selected and divided into 8 groups based on 3 factors: (1) adhesive: G-Premio bond and Single bond universal; (2) application time: shortened time and manufacture's instruction; (3) acid etching mode: self-etching and total-etching. Shear bond strength was measured using a universal testing machine, and fractured surface were observed under scanning electron microscope. Microleakage was evaluated by dye penetration depth. G-Premio bond were not significant different in shear bond strength and microleakage depending on application time of adhesive and acid etching mode. In Single bond universal, shear bond strength of short application time was significantly lower than that of long adhesive application time (p = 0.014). Clinically applicable shear bond strength values (> 17 MPa) were identified in all groups. These results suggested that G-Premio bond be used clinically for a short application time without phosphoric acid etching.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.209-216
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• 2021

Purpose: The purpose of this study is to compare the shear bond strength of resin cement for orthodontic brackets without applying an adhesive primer, to the case of applying an adhesive primer. Materials and Methods: The specimens were divided into three experimental groups, Transbond XT, GC Ortho Connect and Orthomite LC, and the enamel surface was divided into two sections, one with 37% phosphoric acid and the other with 37% phosphoric acid and an adhesive primer or universal adhesive. Each of three types of cement was applied to orthodontic bracket, and after bonding, the shear bond strength was measured. Results: Transbond XT and Orthomite LC significantly increased shear bond strength when orthodontic brackets were bonded after applying an adhesive primer and universal adhesive, respectively. Conclusion: It is expected that application of an adhesive primer or universal adhesive after acid etching will improve shear bond strength of orthodontic brackets in Transbond XT and Orthomite LC.