• Journal of Welding and Joining
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• v.29 no.6
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• pp.49-55
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• 2011

With the development of pre-painted steel sheets for automotive body application, a new joining method is required such as hybrid joining with combination of adhesive bonding and mechanical joining. The objective of this study is to investigate the effect of pre- and post-baking of adhesive bonding on failure mode and strength of hybrid joining of automotive steel sheets. Experiments show that the hybrid joining exhibits better bonding strength and displacement than conventional adhesive joining and mechanical fastening each. Comparison of pre- and post-baked hybrid joining results suggested that baking at $160^{\circ}C$ after mechanical joining was found to have higher joining properties than pre-baking condition. The prebaking condition changed its fracture mode from interfacial to button fracture. The changes in fracture mode with post-baking of hybrid joining was attributed to variation in neck thickness and undercut of joint.

• Journal of the Microelectronics and Packaging Society
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• v.14 no.4
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• pp.49-56
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• 2007

Effects of post-baking treatment conditions on the interfacial adhesion between electroless plated Ni and polyimide film were evaluated using $180^{\circ}C$ peel test. Measured peel strength values monotonically decrease from $38.6{\pm}1.1g/mm\;to\;26.8{\pm}2.2g/mm$ for the variations of post-baking treatment temperatures from $80^{\circ}C\;to\;180^{\circ}C$, respectively. Wet chemical treatment on the polyimide surface produces carboxyl and amide functional groups on the surface which is closely related to the change in interfacial adhesion between electroless Ni and polyimide films. It is speculated that interfacial adhesion seems to be controlled by carbonyl oxygen bonding near cohesive failure region during post-baking treatment.

• Journal of Photoscience
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• v.6 no.3
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• pp.145-151
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• 1999

The use of O-carbamoyloximes as photobase generators was investigated. $\alpha$-Meth-ylbenzilydeneamino phenylcarbamate(2a) and $\alpha$-methyl benzilydeneamino cyclohexylcarbamate(2b) were prepared by the reaction of phenyl or cyclohexyl isocyanates with acetophenone oxime , respectively. Aniline, phenylhydrazine and N, N'-diphenylhydrazine were detected in thephotolysis of 2a and cyclohexylamine and cyclohexylhydrazine in the photolysis of 2b. A monomer having pendant carbamoyloxyimino groups (BGM) was prepared by the reaction fo methancryloyloxyethyl iocyanate with acetophenone oxime, and copolymerized with styrene. The BGM copolymer films turned insoluble on UV irradiation, and the degree of insolubilizationwas increased by post-baking. The photocrosslinking was thought to be due to coupling of resulting pendant aminyl radicals, and the thermal crosslinking was due to association of resulting amino and hydrazino groups by hydrogen bonding. The introduction of epoxy groups into polymer increased the degree of thermal crosslinking by post-baking.

• Journal of Welding and Joining
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• v.27 no.6
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• pp.62-67
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• 2009

Friction stir welding (FSW) was carried out for Al-Mg-Si series aluminum alloys which are being used for automotive body structure. Consequently, Post weld heat treatment (PWHT) was applied to the friction stir welds to evaluate the effect of the paint baking process which is one of the automotive fabrication process on friction stir welded zone (FSWZ) in 443K for 1.2Ks. Grain structure and its crystal orientation distribution was measured about both the as welded specimens and the post weld heat treated specimens. An optical microscope (OM) and an field emission scanning electron microscope (FE-SEM) was used for observing the grain structure and measuring its crystal orientation distribution, respectively. Changes on the grain structure and its crystal orientation distribution were not detected. From the present results, it was confirmed that the paint baking process after FSW do not affect on the grain structure and its crystal orientation distribution of FSWZ. The comprehensive investigations will be performed for various automotive aluminum alloys manufactured by different processes, in the future.

• Applied Chemistry for Engineering
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• v.23 no.1
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• pp.18-22
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• 2012

Photocurable binder for a transparent glass fiber composite was prepared with alicyclic methacrylate and fluorene-based diacrylate. ANOVA (analysis of variance) analysis was used to know main factors affecting the conversion of photocurable binder. It showed radiation intensity and photoinitiator (PI) concentration were main factors. The conversion of photocurable binder was simply increased with radiation intensity. Its increment however was abated with increasing PI concentration. We found that average conversion of the binder measured by FTIR-ATR was 87% when it was exposed to $5J/cm^2$ of UV dose with 5 wt% of PI. Oxime ester type PI was very effective to get a high degree of conversion, but it caused a yellowing problem. Owing to post-baking process, UV cured film showed an improved thermal stability by increase of conversion and removal of volatile organic compounds. TG% at $260^{\circ}C$ of film cured with 5 wt% of PI (TPO+MBF) and $5J/cm^2$ of UV radiation increased from 95.4 to 99.0% by post-baking at $230^{\circ}C$ for 5 min.

• Korean Journal of Optics and Photonics
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• v.8 no.5
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• pp.387-394
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• 1997

The influences of laser-induced damage threshold by the after-processing of $Al_2O_3$ thin films was investigated. The samples were fabricated at the substrate temperature of $100^{\circ}C$, $200^{\circ}C$, $300^{\circ}C$ and $350^{\circ}C$ respectively, and the LIDT were measured by using Nd:YAG laser. After the processing with baking and laser conditioning of the samples, the variation of LIDT was measured. It was found that LIDT was enhanced twice by laser-conditioning process and 1.5 times by baking process. In addition, we measured the chemical properties of the thin film structure before and after the processing by using XPS.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.1
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• pp.130-137
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• 2008

Two-photon stereolithography (TPS) is recognized as a useful process for the fabrication of three-dimensional microstructures. Recently, the need for a two-photon curable resin with high strength increases as 3-D moicrostructures of high aspect ratio or large scale of several hundreds micrometers are required for applications of nano/micro devices in IT/BT. In this work, process parameters of TPS employing the SU-8 which is a representative two-photon curable resin with high strength have been studied for the precise fabrication of 3-D microstructures with high strength. The pre-baking and post-baking processes are studied and the parameter study of the SU-8 in TPS is conducted. Through this work, very small roughness of 12 nm and the minimum aspect ratio of ${\sim}1$ which provides a precise accumulation of layers could be obtained. Using the conditions studied in this work, some 3-D examples are fabricated.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.4
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• pp.581-585
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• 2003

Utilities of kiwi fruit powder prepared from post-mature kiwi fruit in bakery products such as bread and cookie were investigated. The characteristics of bread and cookie with different amounts of kiwi fruit powder were examined through physical measurement (color specific volume, crumb firmness, spread ratio, and extensibility) and seneory evaluation. In baking performance of frozen dough with kiwi fruit powder, $L^{*}$, $a^{*}$, and $b^{*}$ values of crust and specific volume gradually decreased as the concentration of kiwi fruit powder increased. Crumb firmness had significant difference compared to bread without kiwi fruit powder, and sensory characteristics of breads with kiwi fruit powder were more poor than bread without kiwi fruit powder. In a cookie with kiwi fruit powder although specific volume was not significantly different, the spread ratio of cookie and cookie toughness significantly decreased; furthermore, cookie extensibility significantly increased as an amount of kiwi fruit powder increased. Hardness and moistureness of cookies in sensory evaluation had a similar tendency as toughness and extensibility of cookies. Therefore, post-mature kiwi fruit could be utilized to improve the cookie qualities.ies.s.

• Proceedings of the KAIS Fall Conference
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• 2002.11a
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• pp.238-242
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• 2002

본 논문에서는 3차원 마이크로구조물을 위한 새로운 Thick Photoresist(TPR) 공정 기술을 개발하였다. 일반적으로 Thin Photoresist는 얇은 두께로 코팅을 할 수 있다. 그러나 SU-8과 같은 TRP은 몇 십 ㎛ 또는 그 이상으로 코팅이 가능하고 높은 종횡비를 얻을 수 있다. SU-8과 같은 TPR을 사용하여 마이크로구조물을 제작할 때 TPR의 crack들은 bake시의 갑작스런 tool down에 의한 stress에 의해 나타나는데, 이러한 crack들은 마이크로구조물의 도금을 어렵게 만든다. 본 논문에서는 TPR의 코팅, baking 시간 조절, cool down과 PEB(Post Expose Sake) 시간 조절을 통하여 stress에 의해 발생되는 crack이 없는 3차원 마이크로구조물을 제작할 수 있는 새로운 공정 기술을 개발하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.5
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• pp.456-461
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• 2007

In this study, a surface treatment method using accelerated Ar ions was experimented for exposing the carbon nanotubes (CNT) from the screen-printed CNT paste. After making a cathode electrode on the glass substrate, photo sensitive CNT paste was screen-printed, and then back-side was exposed by UV light. Then, the exposed CNT paste was selectively remained by development. After post-baking, the remained CNT paste was bombarded by accelerated Ar ions for removing some binders and exposing only CNTs. As results, the field emission characteristics were strongly depended on the accelerating energy, bombardment time, and the power of RF plasma ion source. When Ar ions accelerated with 100 eV energy from the 100 W RF plasma source are bombarded on the CNT paste surface for 10 min, the emission level and the uniformity were best.