• 한국정밀공학회지
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• 제31권10호
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• pp.873-879
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• 2014

UV curable adhesives with different acrylic functionalities were synthesized for temporary bonding and debonding process in 3D multi-chip packaging process. The aim is to study various factors which have an influence on UV curing. The properties and curing behaviors were investigated by gel fraction, peel strength, probe tack, and shear adhesion failure temperature. The results show that the properties and curing behaviors are dependent on not only acrylic functionalities of binders but also UV doses and coating thickness.

• Current Photovoltaic Research
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• 제5권3호
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• pp.83-88
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• 2017

The growth of intermetallic compounds is an important factor in the reliability of solar cells. Especially, the temperature change in the soldering process greatly affects the thickness of the intermetallic compound layer. In this study, we investigated the intermetallic compound growth by Sn-diffusion in solder joints of solar cells. The thickness of the intermetallic compound layer was analyzed by IR lamp power and hot plate temperature control, and the correlation between the intermetallic compound layer and the adhesive strength was confirmed by a $90^{\circ}$ peel test. In order to investigate the growth of the intermetallic compound layer during isothermal aging, the growth of the intermetallic compound layer was analyzed at $85^{\circ}C$ and 85% for 500 h. In addition, the activation energy of Sn was calculated. The diffusion coefficient of the intermetallic compound layer was simulated and compared with experimental results to predict the long-term reliability.

• Structural Engineering and Mechanics
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• 제57권2호
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• pp.295-313
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• 2016

In this study, the three-dimensional finite element method is used to determine the stress intensity factor in Mode I and Mixed mode of a centered crack in an aluminum specimen repaired by a composite patch using contour integral. Various mesh densities were used to achieve convergence of the results. The effect of adhesive joint thickness, patch thickness, patch-specimen interface and layer sequence on the SIF was highlighted. The results obtained show that the patch-specimen contact surface is the best indicator of the deceleration of crack propagation, and hence of SIF reduction. Thus, the reduction in rigidity of the patch especially at adhesive layer-patch interface, allows the lowering of shear and normal stresses in the adhesive joint. The choice of the orientation of the adhesive layer-patch contact is important in the evolution of the shear and peel stresses. The patch will be more beneficial and effective while using the cross-layer on the contact surface.

• 한국염색가공학회지
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• 제33권4호
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• pp.269-279
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• 2021

In this study, the laminating of TPU film after coating of primer adhesive on the fabrics was applied in order to secure the strength to withstand a fall from a higher altitude by increasing the adhesion between the fabric and the film layer. It seems that the fineness of the yarn and the weave construction have a greater effect than the type of the laminating films. The order of superiority of the laminated fabrics by film type and thickness was the same for 1000 denier and 210 denier fabrics, and the tendency was consistent with the order of superiority in the film properties and peel strength tests. The tear strength of laminating fabrics increased three to four times for 1000 denier fabrics compared to the fabric alone, but it decreased by 2 times for the 210 denier fabrics. Summarizing the above results, it is most appropriate to combine 1000d fabric with three types of laminating films(100~200㎛ thickness) of A(0.2T) or B(0.15T) or D(0.1T) considering the air pressure resistance, the impact resistance during the fall, and the durability against damage during use.

• 한국초전도ㆍ저온공학회논문지
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• 제12권2호
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• pp.9-12
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• 2010

A lamination system using reflow soldering was developed to enhance the mechanical properties of high temperature superconductor (HTS) tape. The laminated coated conductor tape was fabricated using the continuous lamination process. The mean, maximum, and minimum tensile loads in a T-peel test of the laminated coated conductor were 9.9 N, 12.5 N, and 7.6 N, respectively. The critical current ($I_c$) distributions of the non-laminated and laminated coated conductor were compared using anon-contact Hall probe method. The transport $I_c$ nearly matched the non-contact $I_c$; however, some degraded Ic regions were found on the length of 800 cm of laminated coated conductor. We confirmed that the cause of the partially degraded $I_c$ was due to an increase in line tension by (1) solidification induced by a change of composition that usually occurs in molten brass (Cu, Zn) in solder, or (2) non-homogeneity of the thickness of the coated conductor or metal tapes. We suggest that reflow soldering is a promising method for reinforced HTS tape if the controlling solder thickness and lamination guide are modified.

• 한국식품과학회지
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• 제33권2호
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• pp.200-204
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• 2001

'부유' 단감의 MA포장 조건에 따라 $0^{\circ}C$ 저온저장 중 포장내 공기조성 및 과실의 품질 변화를 조사하였다. 처리내용은 포장방법을 1개 열접착, 5개 열접착, 5개 손결속으로 하고, 포장지 두께는 각각 0.03 ㎜, 0.05 ㎜, 0.06 ㎜로 하였다. 조사 결과, 저장 중 포장내 free-volume은 감소하는 경향을 보였다. 특히 열접착 처리구의 free-volume은 처리간 시기적 차이는 있었으나 저장 중 완전히 감소하였다. free-volume의 감소 속도는 포장단위가 크고, 포장지 두께가 얇을수록 빨랐다. 저장중 포장내 산소 농도는 $1.1{\sim}17.1%$, 이산화탄소 농도는 $1.1{\sim}8.3%$ 수준이었고, 저장기간 중 산소 농도는 감소하고, 이산화탄소는 증가하는 경향이었고 포장지가 얇을수록 산소 농도는 높고 이산화탄소 농도는 낮았다. 또한 저장중 이산화탄소 농도가 $4.0{\sim}8.3%$ 수준으로 높게 유지되고, 산소 농도가 $1.1{\sim}4.0%$로 낮게 안정상태로 유지된 0.05 ㎜, 0.06 ㎜ 5개 포장구에서 경도가 높게 유지되었으나, 저장 20주 후 이산화탄소 농도가 8.3%까지 높아진 0.06 ㎜ 5개 열접착 포장구에서 과육갈변과의 발생이 가장 많았다. 반면 산소 농도가 상대적으로 높고 이산화탄소 농도가 비교적 낮은 0.03 ㎜ 포장구와 1개 포장구는 과피흑변과의 발생이 많았다.

• 한국식품저장유통학회지
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• 제2권2호
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• pp.251-257
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• 1995

In order to determine the quality of Citrus unshiu(medium cultivar of satsuma mandarin) produced in Cheju, citrus fruits sampled at sorting places and harvested directly on citrus tree in south and north area of Cheju were analyzed. The fruits were grown in size till early of November, and soluble solids were increased continuously after that. Compared with the quality of citrus fruits as a factor of soluble solids, firmness, total sugar, pH, and color index, the optimum harvest periods were supposed to be reasonable from early of December for C. unshiu Marc. var. yonezawa and C. unshiu Marc. var. hayashi, Fruit weights and peel thickness had a linear correlation with increasing fruit size, but soluble solids and acid contents had not a correlation. The selection of C. unshiu variety was needed to determine by the properties of storage.

• 한국식품저장유통학회지
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• 제6권1호
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• pp.7-10
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• 1999

Physicochemical properties of Satsuma mandarin(Citrus unshiu Marc. var. miyagawa) harvested in middle of November according to production areas of Cheju were investigated. Peel thickness of citrus fruits was ranged from 2.54mm to 3.13mm, and it was lower on fruits harvested in western areas than those of other areas in Cheju. Soluble solids were ranged from 10.1 to 12.0$^{\circ}$Brix, and it was lower on fruits harvested in southern areas. Acid contents of citrus juice were ranged from 1.28% to 1.42%, it was higher on fruits harvested in eastern areas, specific gravity of citrus fruits was ranged between 0.86 and 0.88. Flesh ratio was ranged from 75.1% to 77.6%, it was lower on fruits harvested in southern areas. Soluble solids, acid content and specific gravity harvested in southern areas of below 100m and over 150m sea level altitude were 11.8 and 11.2, 1.43% and 1.40%, 0.87 and 0.9, respectively. Fruits quality harvested in southern areas was better, compared to other harvest areas of Cheju.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1673-1678
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• 2007

The use of flip-chip type electronic package offers numerous advantages such as reduced thickness, improved environmental compatibility, and downed cost. Despite numerous benefits, flip-chip type packages bare several reliability problems. The most critical issue among them is their electrical performance deterioration upon consecutive thermal cycles attributed to gradual delamination growth through chip and adhesive film interface induced by CTE mismatch driven shear and peel stresses. The electronic package in use is heated continuously by itself. When the crack at a weak site of the electronic package occurs, thermal deformationon the chip side is changed. Therefore, we can measure these micro deformations by using Moire interferometry and find out the crack length.

• 한국식품저장유통학회지
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• 제5권1호
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• pp.1-6
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• 1998

Physicochemical properties of early cultivar of Satsuma mandarin(Citrus unshiu Marc. var. miyagawa) according to harvesting year during 1990 to 1995 were investigated. Climatic conditions of every year affected the quality of citrus fruits. Compared to other harvesting years, flesh ratio and soluble solids were higher, but acid content was lower on citrus fruits produced in 1994, as for good climatic conditions during growth of fruits. Especially, acid content of fruits produced in 1993 was higher, compared to those of years, as for low mean temperature and high rainfalls. Fruit weight, peel thickness and soluble solids had a good linear correlation to fruits size, but acid content and flesh ratio had not correlation derived from difference of individual fruits. From the climatic data, the prediction of fruit quality would be possible in some degree before harvest. It seemed recommend to ably the flexibe method by harvesting year for the quality stanardization of citrus fruit.