• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.594-602
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• 2010

Since the requirement of the high density integration and thin package technique of semiconductor have been increasing, the main package type of semiconductor will be a chip scale package (CSP). The changes of diffusion coefficient and moisture content ratio of epoxy resin systems according to the change of liquid type epoxy resin and fillers for CSP applications were investigated. The epoxy resins used in this study are RE-304S, RE310S, and HP-4032D, and Kayahard MCD as hardener and 2-methylimidazole as catalyst were used in these epoxy resin systems. The micro-sized and nano-sized spherical type fused silica as filler were used in order to study the moisture absorption properties of these epoxy molding compound (EMC) according to the change of filler size. The temperature of glass transition (Tg) of these EMC was measured using Dynamic Scanning Calorimeter (DSC), and the moisture absorption properties of these EMC according to the change of time were observed at $85^{\circ}C$ and 85% relative humidity condition using a thermo-hygrostat. The diffusion coefficients in these EMC were calculated in terms of modified Crank equation based on Ficks' law. An increase of diffusion coefficient and maximum moisture absorption ratio with Tg in these systems without filler can be observed, which are attributed to the increase of free volume with Tg. In the EMC with filler, the changes of Tg and maximum moisture absorption ratio with the filler content can be hardly observed, however, the diffusion coefficients of these systems with filler content show the outstanding changes according to the filler size. The diffusion via free volume is dominant in the EMC with micro-sized filler; however, the diffusion with the interaction of absorption according the increase of the filler surface area is dominant in the EMC with nano-sized filler.

• Elastomers and Composites
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• v.43 no.1
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• pp.39-48
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• 2008

Peel strength of epoxy adhesives can be increased by adding some amounts of XNBR. In this case, thermal resistance of the adhesive will be decreased by decrease of glass transition temperature of the adhesive. Epoxy resin modified with siloxane-imide was synthesized to improve thermal resistance and peel strength of the adhesive, after that the properties of modified epoxy resin were compared with the commercial epoxy resin. When 5% XNBR was added to 30% modified epoxy resin, this adhesive showed 0.42 N/mm of peel strength and $155^{\circ}C$ of glass transition temperature. These properties are enough compared to the required properties by the industry, i.e., 0.3 N/mm and $150^{\circ}C$, respectively. Weight loss of the modified epoxy resin by the treatment of nitric acid and 0.1N NaOH was reduced, but weight gain by the humid condition was increased by the presence of benzene ring and imide ring. 30% modified epoxy resin blended with 5% XNBR showed 220% improvement in tensile strength and elongation compared to the case of common epoxy resin. This is due to the flexibility of the siloxane in the modified epoxy resin.

• The Korean Journal of Rheology
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• v.8 no.3_4
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• pp.215-225
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• 1996

평판형의 열가소성 수지를 유리전이온도 이상으로 가열한 다음 압력을 가함으로써 원하는 형상의 제품을 성형하는 열성형공정은 대상 수지가 큰 변형을 일으킬 뿐만 아니라 비선형적 거동을 보이게 된다. 따라서 수지의 변형거동 예측과 최적성형조건의 설정에 많은 어려움과 시행착오를 거치게 되는 바, 열성형 공정의 최적화를 위한 연구의 일환으로 원형 평판위 수지를 대상으로 수지의 부풀림 거동과 이에 따른 두께 분포를 예측할수 있는유한요 소법의 수치모사 알고리듬을 개발하고자 하였다. Piola-Kirchhoff 응력 텐서와 Green 변형 텐서 및 lagrangian 변형 텐서를 사용하여 평판상의 응력-변형에 대한 비선형의 에너지 수 지식을 수립하고 Newton-Raphson 반복수렴법을 이용하여 근사적으로 해석하였으며 수지의 유변학적 구성방정식으로는 neo-Hookean 모델, Mooney-Rivlin 모델 및 Ogden 모델등의 초탄성 모델을 사용하여 그결과를 비교하였다. 수치모사에는 두께가 매우 얇기 때문에 두께 방향의 응력변화를 무시할수 있는 membrane 가정을 도입한 2차원적 해석과 두께 방향의 응력 변화를 고려하는 3차원적 해석을 모두 수행하고 그 차이를 비교하였으며 3차원적 해석 의 경우에는 penalty법을 이용하여 비 압축성을 만족하였다. 일차적으로 내압을 받는 두꺼 운 원통계에 대한 수치모사 해석을 수행하고 완전해와 비교함으로써 개발된 수치모사 알고 리듬의 열성형 공정에의 적용 타당성을 검증하였으며 이를 이용하여 원형 평판의 자유부풀 림거동을 예측한 결과 Treloar 등의 실험결과와 잘 부합함을 확인하였다. 또 간단한 형상의 금형이 있는 경우와 반지름 방향으로의 온도변화에 따른 수지의 변형거동을 해석함으로써 실제 열성형 공정에서 요구되고 있는 성형품의 두께 분포를 균일하게 하기 위한 방안을 제 시하였다.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.05a
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• pp.113-118
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• 2005

Recycle methodology was researched on the HIPS(High Impact Poly Styrene) materials which are used in modern industry widely, For the various mixing ratio between virgin pellets of HIPS and recycled ones, tensile strength and shrinkage ratio were analyzed with injection molding experiments and numerical simulations. In addition, the deviations of dimensional accuracy were observed in accordance with various molding conditions. Molding conditions such as mold and melt temperature were changed by 3 steps. Mixing ratio between virgin pellets of HIPS and recycled ones were under controlled with 15%, 30% and 45%.

• Resources Recycling
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• v.13 no.5
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• pp.23-27
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• 2004

In this study, experimental work was performed to mold tensile specimens by using the injection molding machine. Melt temperature, mold temperature and the mixed ratio of recycled resin were selected as processing parameters for studying the effect of those conditions on the shrinkage, weight, absorption, and tensile strength of molded parts. As a result, the shrinkage was increased according to the higher mold and melt temperature and it was more sensitive to the change of mold temperature. On the other hand, the weight of molded parts was decreased due to the increment of mold and melt temperature. Tensile strength was increased with mold and melt temperature, and it was also easy to change by mold temperature.

• Journal of Conservation Science
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• v.21
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• pp.41-48
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• 2007

The resistance for atmospheric corrosion of the conventional 5 epoxy resins (Araldite rapid, Araldite AW 106, Araldite SV 427, Devcon, and CDK), those were used to restoration of the iron relics, were investigated in this study. Temperature, UV light, and water were chosen for the factors of the atmospheric corrosion. The drastic voluminous changes of the epoxy resins were found at the temperature range between $40^{\circ}C$ and $70^{\circ}C$ After UV exposure, the colors of the epoxy resins were severely changed. In case of the indoor exposure the chroma value(${\Delta}E$) of the resins were less than 2, which showed a little changes of the colors. The result of the water contact angle test was Araldite rapid>AW 106>Devcon>SV 427>CDK. Although the contact angles of the resins were reduced by UV exposure, SV 427 was stable comparatively.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.545-548
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• 2008

불포화 폴리에스테르 수지를 결합재로 사용하여 제작되는 폴리머 콘크리트 맨홀은 조기 고강도 발현, 접착성. 수밀성, 내동결융해성, 내약품성, 내마모성, 전기절연성이 우수하여 프리캐스트로 제작되는 많은 통신용 맨홀에 적용되고 있다. 폴리머 콘크리트의 결합재로 사용되는 불포화 폴리에스테르 수지는 열경화성수지로써, 자체 발열에 의해 거푸집을 탈형할 정도의 초기 경화 반응이 나타나지만, 구조물로서 요구되는 소요 강도를 발휘하기 위해서는 적정 온도에 의한 추가 양생이 반드시 필요하다. 이에 본 논문에서는 폴리머 콘크리트의 휨 강도 시험용 공시체를 사용하여, 다양한 양생 온도 조건 및 양생기간에 따른 휨 강도를 측정하였으며, 이를 가열 촉진 양생에 의한 휨 강도와 비교하여 콘크리트가 소요 강도를 발휘하는데 요구되는 적정 온도와 기간을 도출하였다. 이를 통해 폴리머 큰크리트 맨홀의 품질 확보를 위한 생산 관리와 제품 검사를 체계적이고 효율적으로 수행할 수 있도록 하였다.

• Composites Research
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• v.28 no.3
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• pp.99-103
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• 2015

This paper presents the cure kinetics studies on the cure reaction of thermosetting resin. Above all, change in degree of cure and specific heat capacity according to temperature are observed using DSC and MDSC. The results are analyzed by cure kinetics and specific heat capacity model. Glass transition temperature was also measured to apply to the specific heat capacity model. Model parameters were gained from the modeling result. As a result, behavior of specific heat capacity can be calculated mathematically.

• Journal of Adhesion and Interface
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• v.8 no.4
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• pp.14-22
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• 2007

In the present study, the effect of milled glass powder and liquid-type nitrile rubber (NBR) on the thermal stability of phenolic resin and the dynamic mechanical properties of glass braid/phenolic composites has been investigated by means of thermogravimetric analysis and dynamical mechanical analysis. It was found that both milled glass power and NBR filled in the waterborne phenolic resin significantly influenced the thermal stability of phenolic resins and the storage modulus and tan delta of the composites. The presence of glass powder increased the thermal stability of the phenolic resin, whereas the presence of NBR resulted in the weight loss in the specific temperature range. The thermal stability of the phenolic resins without and with the fillers was dependent not only on the cure temperature but also on the cure time. The variation of the storage modulus and tan ${\delta}$ of strip-type glass braid/phenolic composites was also influenced with the introduction of glass powder and NBR to the phenolic matrix as well as by the cure conditions given.

• Proceedings of the KAIS Fall Conference
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• 2008.11a
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• pp.419-422
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• 2008

ETA(Ethanolamine, 에탄올아민)는 Amine의 일종으로 정밀화학 제품의 중간원료로서 화학제품 제조나 비행기 기관 및 원전 2차계통의 부식방지제, 이산화탄소와 같은 산성 성분을 흡수하는 흡수제로 각종 산업에서 다양하게 사용되고 있는 화학물질이다. 이러한 ETA는 탄소와 질소, 산소로 이루어진 매우 안정된 유기화합물로 상온에서는 휘발성을 띠지만, 산/염기 평형상수가 9 이상이므로 9 이하일 경우에는 수중에 존재하며 COD 및 T-N을 유발하므로 제거해야 한다. 따라서 본 연구에서는 수중에 존재하는 ETA를 제거하기 위해 온도와 농도에 따른 양이온교환 및 재생용액의 농도, 반응시간에 따른 양이온 교환수지 재생특성을 조사하였다. 양이온교환 수지의 이온교환능력은 ETA의 농도 및 온도에 영향을 받았으며 농도와 온도가 증가할수록 파과시간은 단축되었다. 양이온교환 수지의 재생효율은 재생액의 농도 및 반응시간에 영향을 받았으며, 재생액의 농도 및 반응시간이 증가할수록 재생효율은 증가하였다.