• Macromolecular Research
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• v.14 no.3
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• pp.300-305
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• 2006

The chemical structure of a semi-aromatic polyimide-I, which was prepared by the chemical imidization of cyclopentanetetracarboxylic dianhydride and 2,2-bis(4-aminophenyl)hexafluoropropane, was characterized by $^{13}C-NMR$ spectroscopy. The chemically imidized polyimide-I was used for the preparation of a photosensitive polyimide (PSPI) through the addition of benzophenone and benzophenone oxime hexamethylene diurethane (BOHD), a photobase generator containing oxime-urethane groups. The polyimide-I film containing benzophenone and BOHD was not soluble in 2.38 wt% tetrabutylammonium hydroxide solution in $H_2O$. However, it became soluble following irradiation with 310 nm UV light. A positive tone image with a resolution of $5{\mu}m$ was obtained with this PSPI, having sensitivity($D_c$) of $1.2J/cm^2$ and contrast(${\gamma}_p$) of 1.08. Thus, a polyimide, which is not intrinsically photosensitive, can become photosensitive through the addition of a photobase generator containing oxime-urethane groups as a photosensitive compound.

• Laser Solutions
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• v.14 no.1
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• pp.25-29
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• 2011

Micromachining of photosensitive glass by UV exposure, heat treatment, and etching processes is reported. Like photoresist, the photosensitive glass is also classified into positive and negative types by development characteristics. For the positive type, the exposed area is crystallized and etched away during the etching process in HF solution, whereas the unexposed area is crystallized and etched away for the negative type. The crystallized area of the photosensitive glass has an etch rate approximately 30~100 times faster than that of the amorphous area so that it becomes possible to fabricate microstructures in the glass. Based on the unique properties of glass such as high optical transparency, electrical insulation, and chemical/thermal stability, the glass micromachining technique introduced in this work could be widely applied to various devices in the fields of electronics, bio engineering, nanoelectonics and so on.

• Korean Journal of Materials Research
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• v.16 no.9
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• pp.550-556
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• 2006

Photosensitive carbon nanotube (CNT) pastes are explored to develop a CNT field emitter for field emission display (FED) application. We formulated a photosensitive paste including multi-walled CNTs (MWNTs) for screen printing. The photosensitive CNT paste was synthesized by mixing of MWNTs, inorganic fillers (nano metal), organic vehicle, monomers and photo initiator. The CNT paste films were patterned by using backside exposure technique. The CNTs were strongly fixed on a cathode by formation of carbon residue during firing process. For the CNT emitters, current-voltage(I-V) characteristics and images of field emission were evaluated. The emission properties of CNT emitters are dependent on the paste composition. A turn-on electric field for the CNT field emitters is measured to be 1 V/$\mu$m. Additionally, the effect of heat treatment parameter on field emission properties was discussed. The newly formulated photosensitive CNT paste can be potentially applicable to highly reliable CNT field emitters.

• Bulletin of the Korean Chemical Society
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• v.29 no.10
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• pp.2054-2056
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• 2008

• The Korean Journal of Ceramics
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• v.7 no.2
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• pp.58-62
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• 2001

The relationship between the addition of Sb$_2$O$_3$ and the color difference by solarization in photosensitive glasses was investigated. Glasses containing CeO$_2$ and Sb$_2$O$_3$ simultaneously and glasses with only CeO$_2$ were changed reddish and yellowish respectively after exposing to ultra violet ray. Color difference between compositions was represented by dominant wavelength and purity. Since, in glasses containing CeO$_2$ and Sb$_2$O$_3$ simultaneously, Sb$_2$O$_3$ as reduction agent affected Ce$^3+$ ions to increase in glass and more Ce$^4+$ ions were induced than in glasses with only CeO$_2$ during UV irradiation, more electrons released by photo-ionization, which were color centers, were trapped by Ce$^4+$. In conclusion, the introduction of Sb$_2$O$_3$ to photosensitive glasses with CeO$_2$ resulted in the change of color center concentration in glasses and prevented the solarization of photosensitive glasses with CeO$_2$.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.12
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• pp.1639-1645
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• 2002

Micro engine that includes Micro scale combustor is fabricated. Design target was focused on the observation of combustion driven actuation in MEMS scale. Combustor design parameters are somewhat less than the size recommended by feasibility test. The engine structure is fabricated by isotropic etching of the photosensitive glass wafers. Electrode formed by electroplating of the Nickel. Photosensitive glass can be etched isotropically with almost vertical angle. Bonding and assembly of structured photosensitive glass wafer form the engine. Combustor size was determined to be 1 mm scale. Movable piston is engraved inside the wafer. Ignition was done by nickel spark plug which was electroplated with thickness of 40 ${\mu}{\textrm}{m}$. The wafers were bonded by epoxy that resists high temperature. In firing test due to the bonding method and design tolerance pressure buildup by reaction was not confirmed. But ignition, flame propagation and actuation of micro structure from the reaction was observed. From the result basement of design and fabrication technology was obtained.

• Proceedings of the Materials Research Society of Korea Conference
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• 2000.05a
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• pp.77-85
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• 2000

Photosensitive amorphous materials are attractive for the formation of several optical elements by a specific laser beam irradiation. For example the optical fiber gratings prepared by UV laser irradiation are one of the key elements for the recent worldwide progress of wavelength division mutiplexing optical fiber network. This paper reviews the representative studies on the photosensitive materials and the origin of photosensitivity in amorphous oxide materials.

• JSTS:Journal of Semiconductor Technology and Science
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• v.1 no.4
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• pp.232-238
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• 2001

A new DNA purification chip is proposed and fabricated for the sample preparation of Nucleic Acid (NA) probe assay. The proposed DNA purification chip is fabricated using photosensitive glass substrate and polydimethylsiloxane (PDMS) cover fixture. We have successfully captured and eluted the DNA using the fabricated photosensitive glass chip. The fabricated DNA purification chip showed a binding capacity of $15ng/\textrm{cm}^2$and a minimum extractable input concentration of $100copies/200\muL$. The proposed DNA purification chip can be applied for low-cost, disposable sample preparation of NA probe assays.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.369-372
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• 2008

Black matrix and Ag electrode with uniform line pitches were successfully fabricated through the photolithographic process by using the photosensitive black pastes and Ag pastes with optimized photosensitive properties for high resolution PDPs. The photosensitivity of the black and Ag pastes in the photolithographic process was investigated with the variation of photosensitive BM and Ag pastes and the photolithography process conditions. The important components and formulation of the photosensitive BM and Ag paste we discussed.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.3
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• pp.55-63
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• 2011

The convex printing plate in particular securities is classified three physical properties. The main ingredient(component)of photosensitive plastic is composed of thermosetting polyamide. After being hardened specimen at $80^{\circ}C$ is shown to resist highly, the Glass Transition Temperatures of photosensitive plastic are $85^{\circ}C$. When hardened plate has reached at $80^{\circ}C$, abrasion loss is minimized. the cause is considered it is more effective in hardening when the temperature of photosensitive plastic is $80^{\circ}C$-the vitrification temperature of those. The hardness and the durability of the convex printing plate in particular securities are affected to the hardening treatment temperature. And the resolution of original drawing has being better when the durability is superior.