Formation of copper wiring on a polyimide film by laser irradiation to a stable copper-complex film consisting of glyoxylic acid copper complex and methylamine copper complex in air has been investigated. A stable met...Formation of copper wiring on a polyimide film by laser irradiation to a stable copper-complex film consisting of glyoxylic acid copper complex and methylamine copper complex in air has been investigated. A stable metallic copper on the polyimide film was precipitated even in air. Since this copper was generated only in the laser-irradiated parts, direct patterning of copper wiring was possible. It was also found that copper was precipitated by electroless copper plating on the laser-deposited copper wiring and it was possible to thicken the copper wiring by this precipitation. The resistivity of the copper wiring was almost the same as that of the bulk of metallic copper. The developed method—combining laser irradiation to a copper-complex-coated film and electroless copper plating—enables the high-speed deposition of fine copper wiring on a polyimide film in air by a printing process, indicating an inexpensive and useful process for fabricating copper wiring without high vacuum facility and heat-treatment under inert gas.展开更多
The effects of excimer light irradiation on polysilazane coatings formed on PET films with vacuum-evaporated SiO2 coatings and the effects of these coatings on gas barrier characteristics have been investigated. The t...The effects of excimer light irradiation on polysilazane coatings formed on PET films with vacuum-evaporated SiO2 coatings and the effects of these coatings on gas barrier characteristics have been investigated. The temperature during light irradiation has a large effect on the coating’s molecular structure and gas barrier characteristics. When irradiation was performed at 100℃, the polysilazane coating transformed into a silica coating, and a compact silica coating at a much lower temperature than with heat treatment alone was produced. Surface irregularities in the vapor-deposited silica coating were smoothed out by the formation of a polysilazane coating, which was transformed into a compact silica coating when irradiated with light, resulting in a significant improvement in the gas barrier characteristics. The water vapor permeability of the thin coating irradiated with excimer light at 100℃ showed only 0.04 g/m2•day (40℃, 90% RH). According to the results of investigation of temperature variation of water-vapor permeability, it is inferred that the developed film has an excellent gas barrier value, namely, 4.90 × 10–4 g/m2•day at 25℃. This gas barrier coated PET film is transparent and flexible, and can be used in the fabrication of flexible electronics. Also, the proposed fabrication method effectively provides a simple low-cost and low-temperature fabrication technique without the need for high vacuum facility.展开更多
Preparation of a glyoxylic acid copper complex and fabrication of fine copper wire by CO2 laser irradiation in air to a thin film of that complex have been investigated. Irradiating laser to the complex thin film spin...Preparation of a glyoxylic acid copper complex and fabrication of fine copper wire by CO2 laser irradiation in air to a thin film of that complex have been investigated. Irradiating laser to the complex thin film spin-coated on a glass substrate, thin film of metallic copper was fabricated in areas that were subjected to laser irradiation in air. The thickness of this thin copper film was approx. 30 to 40 nm, and as non-irradiated areas were etched and removed by a soluble solvent of the copper complex, fine copper wire with 200 μm width was formed by laser direct patterning. The resistivity of this thin copper film depended on the irradiation intensity of the laser and was 3.0 × 10–5 Ω·cm at 12 W intensity (sweep speed: 20 mm/s). This method enables the high-speed deposition of copper wiring in air by a printing process, indicating an inexpensive and useful process for fabricating copper wiring.展开更多
A new flexible substrate for flexible electronics has been developed. The developed substrate consists of an ultra thin glass and TAC (triacethyl cellulose) film. An ultra thin glass and TAC film were joined with TEOS...A new flexible substrate for flexible electronics has been developed. The developed substrate consists of an ultra thin glass and TAC (triacethyl cellulose) film. An ultra thin glass and TAC film were joined with TEOS-DAC (TEOS: tetraethyl orthosilicate, DAC: diacethy cellulose) adhesive resin synthesized by sol-gel method by means of thermo-compression bonding. This substrate has high transparency in visible-light region (90%), high flexibility (torsion strength and bending strength) and high gas barrier characteristics due to an ultra thin glass. The newly-developed substrate is superior to the substrates fabricated with commercially available adhesive resin in the same way in characteristics of heat resistance, transparency and flexibility.展开更多
A high-efficiency synthesis method for a latent pigment of red pigment diketo-pyrrolo-pyrrole (Pig. Red 272:272DPP), which is important as a functional organic pigment, was investigated, and the investigation results ...A high-efficiency synthesis method for a latent pigment of red pigment diketo-pyrrolo-pyrrole (Pig. Red 272:272DPP), which is important as a functional organic pigment, was investigated, and the investigation results revealed that irradiation of microwaves (MWs) for several seconds to 272 DPP in NMP (N-methyl-2-pyrrolidone) solvent yielded DPP latent pigment (272DPP-BOC) at a high yield of 86.2%. Two kinds of latent-pigment crystals, namely, red and yellow, were obtained by recrystallization, and it was found that the fluorescence-emission properties of the two kinds differ significantly. Single-crystal X-ray structural analysis showed that the difference in the fluorescence-emission properties of the two types is derived from the difference in their crystal structures.展开更多
Flexible electronics have been recently paid much attention. A flexible substrate (Organic resin film) is indispensable component for flexible devices. Though PET film is low-cost organic film, low heat-resistance of ...Flexible electronics have been recently paid much attention. A flexible substrate (Organic resin film) is indispensable component for flexible devices. Though PET film is low-cost organic film, low heat-resistance of PET film limits its application as a flexible device substrate. We have developed heat-resistant PET which does not deteriorate even at 190°C heat treatment for one hour. An excimer light was irradiated onto a polysi-lazane (PHPS: perhydropolysilane)-coated film to form a dense silicon-dioxide (SiO2) layer on a PET film, and the heat-resistance property of the formed film was examined. Changes of surface state and cross-sectional structure of the formed film due to heat treatment were investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM). Compared to normal PET, which is deteriorated and whitened by heat treatment of about 110°C - 120°C, the SiO2-coated PET film maintains transparency and does not deteriorate after heat treatment at 180°C - 190°C for one hour. This high heat resistance is due to a dense SiO2 film formed on the surface that prevents surface precipitation and crystallization of low-molecular-weight oligomers (which are the cause of thermal degradation of PET). It is expected that enhancing the heat resistance of PET—which has high versatility and low cost—to about 180°C to 190°C will allow SiO2-film-coated PET to be developed as a film substrate for flexible devices.展开更多
Hydrogen has been recently attracted much attention with respect to high energy-conversion efficiency and low environmental burden. However, hydrogen gas is dangerous due to an explosive gas and a fast combustion rate...Hydrogen has been recently attracted much attention with respect to high energy-conversion efficiency and low environmental burden. However, hydrogen gas is dangerous due to an explosive gas and a fast combustion rate. Therefore, the development of hydrogen sensor with high accuracy and reliability that can detect hydrogen easily is required. Especially, a flexible hydrogen sensor is useful because it has a high degree of freedom with respect to the shape of location in which the sensor is to be located. A flexible hydrogen sensor—namely, a WO3 thin film formed on a PET film by the sol-gel method using photo irradiation—based on gasochromism of WO3 was developed. By irradiating a thin film, which was prepared by using WO3 precursor solution synthesized by the sol-gel method, with ultraviolet rays, a high-purity WO3 film could be prepared on PET at low temperature. The sensor was structured as a polystyrene (PS) film containing palladium (Pd) laminated on a WO3 film. The WO3 layer was porous, so the PS containing Pd atoms solution penetrated the WO3 layer. WO3 reacted with hydrogen gas and instantly turned blue as the transmittance of the WO3 layer changed. The sensor showed high reactivity even for hydrogen concentration below 4% (1%, 0.5%, 0.25%, and 0.1%), which was the lower limit of hydrogen ignition, and a linear relationship between hydrogen concentration and change in transmittance was found. Moreover, the resistance of the WO3 film significantly and instantaneously changed due to hydrogen-gas exposure, and the hydrogen concentration and resistance change showed a linear relationship. It is therefore possible to quantitatively detect low concentrations of hydrogen by using changes in transmittance and resistance as indices. Since these changes occur selectively under hydrogen at room temperature and normal pressure, they form the basis of a highly sensitive hydrogen sensor. Since the developed sensor is flexible, it has a high degree of freedom with respect to the shape of location in which the sensor is to be展开更多
文摘Formation of copper wiring on a polyimide film by laser irradiation to a stable copper-complex film consisting of glyoxylic acid copper complex and methylamine copper complex in air has been investigated. A stable metallic copper on the polyimide film was precipitated even in air. Since this copper was generated only in the laser-irradiated parts, direct patterning of copper wiring was possible. It was also found that copper was precipitated by electroless copper plating on the laser-deposited copper wiring and it was possible to thicken the copper wiring by this precipitation. The resistivity of the copper wiring was almost the same as that of the bulk of metallic copper. The developed method—combining laser irradiation to a copper-complex-coated film and electroless copper plating—enables the high-speed deposition of fine copper wiring on a polyimide film in air by a printing process, indicating an inexpensive and useful process for fabricating copper wiring without high vacuum facility and heat-treatment under inert gas.
文摘The effects of excimer light irradiation on polysilazane coatings formed on PET films with vacuum-evaporated SiO2 coatings and the effects of these coatings on gas barrier characteristics have been investigated. The temperature during light irradiation has a large effect on the coating’s molecular structure and gas barrier characteristics. When irradiation was performed at 100℃, the polysilazane coating transformed into a silica coating, and a compact silica coating at a much lower temperature than with heat treatment alone was produced. Surface irregularities in the vapor-deposited silica coating were smoothed out by the formation of a polysilazane coating, which was transformed into a compact silica coating when irradiated with light, resulting in a significant improvement in the gas barrier characteristics. The water vapor permeability of the thin coating irradiated with excimer light at 100℃ showed only 0.04 g/m2•day (40℃, 90% RH). According to the results of investigation of temperature variation of water-vapor permeability, it is inferred that the developed film has an excellent gas barrier value, namely, 4.90 × 10–4 g/m2•day at 25℃. This gas barrier coated PET film is transparent and flexible, and can be used in the fabrication of flexible electronics. Also, the proposed fabrication method effectively provides a simple low-cost and low-temperature fabrication technique without the need for high vacuum facility.
文摘Preparation of a glyoxylic acid copper complex and fabrication of fine copper wire by CO2 laser irradiation in air to a thin film of that complex have been investigated. Irradiating laser to the complex thin film spin-coated on a glass substrate, thin film of metallic copper was fabricated in areas that were subjected to laser irradiation in air. The thickness of this thin copper film was approx. 30 to 40 nm, and as non-irradiated areas were etched and removed by a soluble solvent of the copper complex, fine copper wire with 200 μm width was formed by laser direct patterning. The resistivity of this thin copper film depended on the irradiation intensity of the laser and was 3.0 × 10–5 Ω·cm at 12 W intensity (sweep speed: 20 mm/s). This method enables the high-speed deposition of copper wiring in air by a printing process, indicating an inexpensive and useful process for fabricating copper wiring.
文摘A new flexible substrate for flexible electronics has been developed. The developed substrate consists of an ultra thin glass and TAC (triacethyl cellulose) film. An ultra thin glass and TAC film were joined with TEOS-DAC (TEOS: tetraethyl orthosilicate, DAC: diacethy cellulose) adhesive resin synthesized by sol-gel method by means of thermo-compression bonding. This substrate has high transparency in visible-light region (90%), high flexibility (torsion strength and bending strength) and high gas barrier characteristics due to an ultra thin glass. The newly-developed substrate is superior to the substrates fabricated with commercially available adhesive resin in the same way in characteristics of heat resistance, transparency and flexibility.
文摘A high-efficiency synthesis method for a latent pigment of red pigment diketo-pyrrolo-pyrrole (Pig. Red 272:272DPP), which is important as a functional organic pigment, was investigated, and the investigation results revealed that irradiation of microwaves (MWs) for several seconds to 272 DPP in NMP (N-methyl-2-pyrrolidone) solvent yielded DPP latent pigment (272DPP-BOC) at a high yield of 86.2%. Two kinds of latent-pigment crystals, namely, red and yellow, were obtained by recrystallization, and it was found that the fluorescence-emission properties of the two kinds differ significantly. Single-crystal X-ray structural analysis showed that the difference in the fluorescence-emission properties of the two types is derived from the difference in their crystal structures.
文摘Flexible electronics have been recently paid much attention. A flexible substrate (Organic resin film) is indispensable component for flexible devices. Though PET film is low-cost organic film, low heat-resistance of PET film limits its application as a flexible device substrate. We have developed heat-resistant PET which does not deteriorate even at 190°C heat treatment for one hour. An excimer light was irradiated onto a polysi-lazane (PHPS: perhydropolysilane)-coated film to form a dense silicon-dioxide (SiO2) layer on a PET film, and the heat-resistance property of the formed film was examined. Changes of surface state and cross-sectional structure of the formed film due to heat treatment were investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM). Compared to normal PET, which is deteriorated and whitened by heat treatment of about 110°C - 120°C, the SiO2-coated PET film maintains transparency and does not deteriorate after heat treatment at 180°C - 190°C for one hour. This high heat resistance is due to a dense SiO2 film formed on the surface that prevents surface precipitation and crystallization of low-molecular-weight oligomers (which are the cause of thermal degradation of PET). It is expected that enhancing the heat resistance of PET—which has high versatility and low cost—to about 180°C to 190°C will allow SiO2-film-coated PET to be developed as a film substrate for flexible devices.
文摘Hydrogen has been recently attracted much attention with respect to high energy-conversion efficiency and low environmental burden. However, hydrogen gas is dangerous due to an explosive gas and a fast combustion rate. Therefore, the development of hydrogen sensor with high accuracy and reliability that can detect hydrogen easily is required. Especially, a flexible hydrogen sensor is useful because it has a high degree of freedom with respect to the shape of location in which the sensor is to be located. A flexible hydrogen sensor—namely, a WO3 thin film formed on a PET film by the sol-gel method using photo irradiation—based on gasochromism of WO3 was developed. By irradiating a thin film, which was prepared by using WO3 precursor solution synthesized by the sol-gel method, with ultraviolet rays, a high-purity WO3 film could be prepared on PET at low temperature. The sensor was structured as a polystyrene (PS) film containing palladium (Pd) laminated on a WO3 film. The WO3 layer was porous, so the PS containing Pd atoms solution penetrated the WO3 layer. WO3 reacted with hydrogen gas and instantly turned blue as the transmittance of the WO3 layer changed. The sensor showed high reactivity even for hydrogen concentration below 4% (1%, 0.5%, 0.25%, and 0.1%), which was the lower limit of hydrogen ignition, and a linear relationship between hydrogen concentration and change in transmittance was found. Moreover, the resistance of the WO3 film significantly and instantaneously changed due to hydrogen-gas exposure, and the hydrogen concentration and resistance change showed a linear relationship. It is therefore possible to quantitatively detect low concentrations of hydrogen by using changes in transmittance and resistance as indices. Since these changes occur selectively under hydrogen at room temperature and normal pressure, they form the basis of a highly sensitive hydrogen sensor. Since the developed sensor is flexible, it has a high degree of freedom with respect to the shape of location in which the sensor is to be
