• Title/Summary/Keyword: finish coating

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Sn-Ag-Cu Solder Joint Properties on Plasma Coated Organic Surface Finishes and OSP (플라즈마 유기막과 OSP PCB 표면처리의 Sn-Ag-Cu 솔더 접합 특성 비교)

  • Lee, Tae-Young;Kim, Kyoung-Ho;Bang, Jung-Hwan;Park, Nam-Sun;Kim, Mok-Soon;Yoo, Sehoon
    • Journal of the Microelectronics and Packaging Society
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    • v.21 no.3
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    • pp.25-29
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    • 2014
  • Plasma organic thin film for PCB surface finish is a potential replacement of the conventional PCB finishes because of environment-friendly process, high corrosion-resistance and long shelf life over 1 year. In this study, solder joint properties of the plasma organic surface finish were estimated and compared with OSP surface finish. The plasma surface finish was deposited by chemical vapor deposition from fluorine-based precursors. The thickness of the plasma organic coating was 20 nm. Sn-3.0Ag-0.5Cu (SAC305) solder was used as solder joint materials. From a salt spray test, the plasma organic coating had higher corrosion resistance than the OSP surface finish. The spreadability of SAC305 on plasma organic coating was higher than that on OSP surface finish. SEM and TEM micrographs showed that the interfacial microstructure of the plasma surface finish sample were similar to that of the OSP sample. Solder joint strength of the plasma finish sample was also similar to that of the OSP finished sample.

Preferential face coating of knitted PET fabrics via UV curing for water- and oil-repellent finish (자외선 경화에 의한 PET 니트직물의 편면 발수발유 가공)

  • Jeong, Yong-Kyun;Jeong, Yongjin;Jang, Jinho
    • Textile Coloration and Finishing
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    • v.17 no.6 s.85
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    • pp.27-35
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    • 2005
  • Conventional pad- dry-cure(thermo-fixation) process usually produces functional performance on both sides of a fabric. UV curing technique was applied to impart water- and oil-repellent finish effective only on the face of a PET knitted fabric. The preferential one-side coating, by virtue of the limited penetration of UV light, was achieved by W curing after padding of a fluorocarbon agent without special coating or printing equipments. The difference in the functional property of face and back sides was examined by measuring water and oil repellency at each side of the treated fabric. The influence of pre/post-irradiation dose and agent concentration on the performance of the finished fabrics were investigated. While increase in both resin concentration and post-irradiation did not have significant effect on the finish, UV pre-irradiation of PET fabrics caused remarkable influence presumably due to appropriate surface modification of PET fabrics required for facile wetting of the resin. The dimensional stability and color change of the UV cured fabrics measured by FAST and reflectance spectrophotometry showed significantly decreased color difference and increased percent extension compared with the samples pre-irradiated without agent application.

Heating & Drying Characteristics of Coating Layer by Induction Heating and Short-wave Infrared Heating (유도가열 및 근적외선 가열방법에 의한 표면처리 강판 도포층의 가열 및 건조 특성)

  • Kim T. S.;Yang J. W.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2004.08a
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    • pp.249-257
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    • 2004
  • Drying and curing characteristics of PCM resins using the induction heater and short-wave infrared emitter module was studied to develop a compact oven system for the high speed CCL and post-treatment equipment. Drying of the polyester resins using the induction heater and infrared heater showed that the blistering tendency of polyester resin coating increased regardless of additives and colors of resins as the heating rate and/or dry film thickness increased. The blistering of polyester resin coating layer occurred when the heating speed was over than $25^{\circ}C/sec$ for the dry film thickness of $19\~20um$, which is the typical thickness of finish coating in CCL. So did it when the heating speed was over than $40^{\circ}C/sec$ for the dry film thickness over than 10 um. The heating efficiency of paint coated steels by the infrared heating was strongly dependent on the colors of paint coating and generally increased for the dark surface and/or coating. But the faster drying of the PCM resin coatings increased the blistering tendency of coating layer. The blistering limit for the typical finish coating by the infrared heating was estimated as the heating rate slower than $20^{\circ}C/sec$ regardless of colors of PCM resins.

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Effect of Disperse Dyeing on UV-curable Flame-retardant Finish of PET Fabrics (분산염료 염색공정이 PET직물의 UV경화형 방염가공에 미치는 영향)

  • Jeong, Yong-Kyun;Jang, Jin-Ho
    • Textile Coloration and Finishing
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    • v.20 no.2
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    • pp.66-74
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    • 2008
  • Effect of disperse dyeing on flame retardant finishing of PET fabrics via UV curing using three UV curable phosphorous-containing methacrylates and ammonium polyphosphate(APP) was investigated. The dye fixation and flame retardancy of PET fabrics did not change significantly with excellent durability to five laundering cycles irrespective of the dyeing and finishing sequence. However, the flame retardancy of Pekoflam-treated fabrics was lower than that of the UV treated and decreased substantially when heat treatment was carried out before the dyeing. The dyeability of the flame-retardant PET fabrics was not affected in the case of UV curing of the methacrylates alone. However, UV finishing after the dyeing caused significant decrease in K/S and ${\Delta}E$ due to changed refraction and inherent color of surface coating of the UV curable monomers and APP. Whereas the heat treatment with Pekoflam decreased both color fastness to laundering and sublimation, surprisingly the UV finish of PET fabrics before and after the dyeing increased the color fastness probably resulting from the presence of photopolymerized surface layer on the fabrics.

Effect of Ball End Mill Geometry and Cutting Conditions on Machinability of Hardened Tool Steel

  • Jang, Dong-Y.;Won, S.-T.
    • KSTLE International Journal
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    • v.3 no.1
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    • pp.17-22
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    • 2002
  • Roughing of tool steel in its hardened state represents a real challenge in the die and meld industry and process improvement depends on research of tool material, coating technique, and lubrication. However, roughing of hardened steels generates extreme heat and without coolant flooding, tool material cannot withstand the high temperature without choosing the right tools with proper coating. This research conducted milling tests using coated ball end mills to study effects of cutting conditions and geometric parameters of ball end mills on the machinability of hardened tool steel. KP4 steel and STD 11 heat treated steels were used in the dry cutting as the workpiece and TiAIN coated ball end mills with side relief angle of 12$^{\circ}$ was utilized in the cutting tests. Cutting forces, tool wear, and surface roughness were measured in the cutting tests. Results from the experiments showed that 85 m/min of cutting speed and 0.32 mm/rev of feed rate were optimum conditions for better surface finish during rough cutting and 0.26mm/rev with the same cutting speed are optimum conditions in the finish cutting.

Breathable Waterproof Finish of PET Fabrics via Microporous UV Coating of Polyurethane Diacrylate (폴리우레탄 디아크릴레이트의 미세다공성 UV코팅에 의한 PET 직물의 투습방수가공)

  • Koo, Gwang-Hoe;Jang, Jin-Ho
    • Textile Coloration and Finishing
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    • v.22 no.3
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    • pp.239-245
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    • 2010
  • Breathable waterproof PET fabrics were prepared by the UV coating of UV-curable polyurethaneacrylate(PUA) formulation mixed with polyethyleneglycol(PEG) as a water soluble pore former. The dispersed PEG in the UV-cured coating was extracted by warm water, which can generate individual circular pores uniformly distributed all over the coating instead of pore channels. Accordingly the moisture permeability of the microporously coated fabrics increased substantially with increasing PEG addition without significant reduction of hydrostatic pressure. Also the silicone diacrylate addition in the formulation was beneficial in increasing the hydrostatic pressure. The UV-based microporous coating can be an alternative to conventional thermal curing of solventborne polyurethane coating owing to the enhanced environment friendliness and energy saving.

-A Study on the Thermal Performance of T.W System with Various Wall Surface Finishes- (집열면의 마감상태에 따른 축열벽 시스템의 열성능 변화에 관한 연구)

  • 송국섭;이언구;이명호
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1993.05a
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    • pp.64-69
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    • 1993
  • The solar energy collection of a passive solar system depends on the finish of collecting surfaces. In this study, the test models of T.W system with different wall surface finishes were constructed, and the temperature distribution through the models was monitored. At the same time, a computer program based on F.D.M was developed in order to simulate various surface finishes. The difference of indoor temperature between the model with white color finish ($\alpha$=0.25) and the one with black color finish ($\alpha$=0.95) was about 1$0^{\circ}C$. For the wall with selective coating, the indoor temperature was 4-5$^{\circ}C$ higher than that of red brick wall, and 3-4$^{\circ}C$ higher than that of wall with black paint.

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A Study on the transition of luster material­after 20th century­ (광택소재의 변화에 대한 연구­20세기 이후)

  • 백천의
    • Journal of the Korea Fashion and Costume Design Association
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    • v.2 no.2
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    • pp.137-154
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    • 2000
  • The purpose of this study is to investigate the transition of luster material after the tweentieth century. This study was conducted by means of designer collection, journal of fashion, museum data, fabric exhibition and Internet data. The results of this study were as follows: Before the synthetic fiber period, the luster materials were used satin, chamuse, gauze, damask brocade and velvet, except cashmere, mohair and rayon. They are made from silk by the way of giving difference surface property. But since 1960s, it has used not only synthetic fiber with smooth surface but also vinyl, latex, natural leather, synthetic leather and metal. Luster material recently has a tendency to natural and soft shiny, example silket finish, chintz finish, silico coating finish with paper touch feel and so forth.

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Prediction of Long-Term Carbonation Depth by Measurement of the Air Permeability Coefficient of Coating on Concrete (콘크리트에 도포된 도막의 투기계수 측정을 통한 장기 중성화 깊이 예측)

  • Park, Dong-Cheon;Nam, Min-Seok;Kim, Yong-Ro;Ko, Hyo-Jin;Ryu, Dong-Woo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.05a
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    • pp.113-114
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    • 2023
  • This study measured the thickness and speculation coefficient of the coating for existing buildings and calculated the diffusion coefficient of the coating to predict the depth of carbonation through numerical analysis in order to evaluate the impact of the external finish and local environment. As a result, it was possible to predict the short-term and long-term carbonation depth of reinforced concrete buildings coated with coating film with considerable reliability.

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Evaluation on Performance of Surface Protectors for Protecting Reinforced Concrete Structures (철근 콘크리트 구조물을 보호하기 위한 표면 보호재의 성능 평가)

  • An, Young-Ki;Jang, Suk-Hwan;Chung, Young-Jun;Nam, Yong-Hyuk
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.1
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    • pp.217-223
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    • 2005
  • This study is on the evaluation of three kinds of surface protectors for protecting reinforced concrete against corrosion of reinforcing steel by chloride attack and carbonation. In this study, the test has been carried out on the performance of specimens applied with surface protectors for anti-corrosion and anti-carbonation. The result showed that specimens applied with the three kinds of surface protectors, were excellent in resistance to the corrosion of reinforcing steel and carbonation. Especially the specimen applied with finish coating in conjunction with hydrophobic primer showed great reduction in the corrosion of reinforcing steel and carbonation.