Browsing by Author "Huang, Kuo-Cheng"

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Characteristics of Ni-Ir and Pt-Ir hard coatings surface treated by pulsed Nd:YAG laser
(2010-12-25)
Tseng, Shih-Feng
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Hsiao, Wen-Tse
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Huang, Kuo-Cheng
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Chen, Ming-Fei
;
Lee, Chao-Te
The subjects of the presented paper are to develop a laser surface treatment technology for the protective coatings of glass-molding dies and to better understand the interaction between laser beam and materials coated on the die surface. A variety of alloy films, including Ir-25 at.% Pt. Ir-50 at.% Pt, Ir-75 at.% Pt. Ir-25 at.% Ni, Ir-50 at.% Ni, and Ir-75 at.% Ni compositions are deposited by the ion source assisted magnetron sputtering system (ISAMSS). A Cr layer that functioned as a buffer layer is deposited between the alloy film and die surface. After an alloy film and the buffer Cr layer were sequentially coated on tungsten carbide (WC) surface, Nd:YAG laser was directly applied in the writing process. The temperature profile of the film stack structure is simulated by ANSYS software. The surface roughness was analyzed by atomic force microscopy (AFM) to compare the coating surface roughness before and after the laser surface treatments. The treated coatings for oxidation prevention test were examined by energy dispersive x-ray spectrometry (EDS). Nanoindentation instrument was performed to evaluate microhardness and reduced modulus of the coatings. The cross-sectional structures between the hard coating layer and buffer layer were also inspected by a scanning electron microscope (SEM). The Pt-Ir and Ni-Ir film coatings are unable to withstand the working temperature over 1500 degrees C, which is considered for quartz molding process and hot embossing process. The films showed high roughness, low microhardness and low reduced modulus because the film oxidation occurred in a high working temperature process. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.
Development of a Novel Rapid Manufacturing Process for Micro-Cylindrical Lens Array
(2011)
Huang, Chien-Yao
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Huang, Kuo-Cheng
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Chen, Jun-Cheng
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Chang, Keng-Souo
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Tseng, Shih-Feng
This paper proposed a novel method to fabricate micro-cylindrical lens array (mu-CLA) by using wire electrical discharge machining (WEDM) and precision glass molding (PGM) technique. Micro slits fabricated on the surface of tungsten carbide mold material with outline dimensions from 0.3mm to 2.1mm, the width and depth of 1 mm. The PGM processing parameters including width of slits, molding temperature, molding force and stroke were discussed. Moreover, the characteristics of mu-CLA were measured by contact profilometer. In addition, the relationship between the dimensions of the slit on tungsten carbide mold and the characteristics of mu-CLA also discussed.
Fabrication of a double-sided micro-lens array by a glass molding technique
(2011-08-01)
Huang, Chien-Yao
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Hsiao, Wen-Tse
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Huang, Kuo-Cheng
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Chang, Keng-Souo
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Chou, Hsiao-Yu
In recent years, micro-lens arrays (MLAs) have become important elements of optical systems. One function of MLAs is to create a uniform intensity of light. Compared with one-sided MLAs, the uniformity of light intensity increases with double-sided MLAs. MLAs fabricated by glass can be used in higher temperature environments or in high-energy systems. Glass-based MLAs can be fabricated by laser machining, photolithography, precision diamond grinding process and precision glass molding (PGM) technologies, but laser machining, photolithography and precision diamond grinding process technologies are not the perfect approach for mass production. Therefore, this paper proposes a method to fabricate a mold by laser micro-machining and a double-sided MLA by a PGM process. First, a micro-hole array was fabricated on the surface of a silicon carbide mold. A double-sided MLA using two molds was then formed by a PGM process. In this paper, the PGM process parameters including molding temperature and molding force are discussed. Moreover, the profile of a double-sided MLA is discussed. Finally, a double-sided MLA with a diameter of 20 mm, and lenses with a height of 52 mu m, a radius of 851 mu m and a pitch of 700 mu m were formed on glass.
Glass biochip fabrication by laser micromachining and glass-molding process
(2012-03-01)
Huang, Chien-Yao
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Kuo, Chao-Hui
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Hsiao, Wen-Tse
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Huang, Kuo-Cheng
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Tseng, Shih-Feng
Due to their low cost, small size, and high-speed performance, biochips are often used in various bio-experiments. Compared with polymer-based biochips, glass-based substrates are less sensitive to heat and organic environments. This study presents a hybrid processing approach that uses laser micromachining (LMM) and precision glass molding (PGM) techniques to mass-produce glass-based biochips. A silicon carbide (SiC) mold with an outside diameter of 20 mm was used to hot emboss biochip channels measuring 200 mu m wide and 185 mu m deep. This study also identifies the optimal conditions for glass molding when processing soda-lime glass for biochip applications, and discusses the influence of the major processing parameters on biochip channel depth. This study uses the Taguchi method to assess the effects of several molding parameters on larger-the-better performance characteristics. The experiments in this study consider the effects of several molding parameters, such as molding temperature, pressing force, moving speed, temperature holding time, and vacuum environment, to achieve optimum characteristics for biochip channels. Orthogonal array analysis indicates that the optimal process parameters includes a 620 degrees C molding temperature, 1 kN pressing force, 5 mm/min moving speed, 60s temperature holding time, and a vacuum-free environment. This study also investigates the surface roughness of glass biochip channels. (C) 2011 Elsevier B.V. All rights reserved.
Hydrophobic Templates with Rough Patterns Fabricated by Laser Micromachining for Liquid Droplets Generation
(2011)
Tseng, Shih-Feng
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Huang, Kuo-Cheng
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Chiang, Donyau
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Chen, Ming-Fei
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Hsiao, Sheng-Yi
This paper presents an approach to utilize high precision pulsed Nd:YAG laser to fabricate a rough array-pattern on a soda-lime glass plate by a laser-induced backside writing (LIBW) process, and a laser-induced plasma assisted ablation (LIPAA) technique. The current study investigates the effect of process parameters such as single-shot laser exposure time and number of passes on the material removal rate. After depositing 695 nm thick Teflon thin film on the glass plate, the surface of the laser micro-machined template becomes hydrophobic. The surface roughness, annular groove profile and surface micrograph were measured by an atomic force microscope, a profilometer, and a scanning electron microscope, respectively. A uniform liquid droplet by the sessile drop method is generated on the hydrophobic template. Droplet characteristics, such as contacted angle, size, and shape, are measured with a surface tension analyzer and microscope. This work also discusses the relationship between the formed droplets and the process recipe of the micro-machined template. The proposed approach can apply to future for uniform lens array formation.
Laser scribing of indium tin oxide (ITO) thin films deposited on various substrates for touch panels
(2010-12-15)
Tseng, Shih-Feng
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Hsiao, Wen-Tse
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Huang, Kuo-Cheng
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Chiang, Donyau
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Chen, Ming-Fei
In this study, a Nd:YAG laser with wavelength of 1064nm is used to scribe the indium tin oxide (ITO) thin films coated on three types of substrate materials, i.e. soda-lime glass, polycarbonate (PC), and cyclic-olefin-copolymer (COC) materials with thickness of 20 nm, 30 nm, and 20 nm, respectively. The effect of exposure time adjusted from 10 mu s to 100 mu s on the ablated mark width, depth, and electrical properties of the scribed film was investigated. The maximum laser power of 2.2W was used to scribe these thin films. In addition, the surface morphology, surface reaction, surface roughness, optical properties, and electrical conductivity properties were measured by a scanning electron microscope, a three-dimensional confocal laser scanning microscope, an atomic force microscope, and a four-point probe. The measured results of surface morphology show that the residual ITO layer was produced on the scribed path with the laser exposure time at 10 mu s and 20 mu s. The better edge qualities of the scribed lines can be obtained when the exposure time extends from 30 mu s to 60 mu s. When the laser exposure time is longer than 60 mu s, the partially burned areas of the scribed thin films on PC and COC substrates are observed. Moreover, the isolated line width and resistivity values increase when the laser exposure time increases. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.
Mechanical and optoelectric properties of post-annealed fluorine-doped tin oxide films by ultraviolet laser irradiation
(2011-06-01)
Tseng, Shih-Feng
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Hsiao, Wen-Tse
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Chiang, Donyau
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Huang, Kuo-Cheng
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Chou, Chang-Pin
The fluorine-doped tin oxide (FTO) thin film deposited on a soda-lime glass substrate was annealed by a defocus ultraviolet (UV) laser irradiation at ambient temperature. The mechanical and optoelectric properties of FTO films annealed by using the various laser processing parameters were reported. After the FTO films were subjected to laser post-annealing, the microhardness were slightly less but the reduced modulus values were larger than that of unannealed FTO films, respectively. The average optical transmittance in the visible waveband slightly increased with increasing the laser annealing energy and scan speed. Moreover, all the sheet resistance of laser annealed films was less than that of the unannealed ones. We found that the sheet resistance decrease was obviously influenced by annealing. The suitable annealing conditions could maintain the film thickness and relief the internal stress generated in the film preparation process to improve the electrical conductivity via decreasing laser energy or increasing scan speed. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.
Mechanical Properties of Pt-Ir and Ni-Ir Binary Alloys for Glass-Molding Dies Coating
(2011-10-01)
Tseng, Shih-Feng
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Lee, Chao-Te
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Huang, Kuo-Cheng
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Chiang, Donyau
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Huang, Chien-Yao
In this study, the different compositions of Pt-Ir and Ni-Ir alloys were deposited by utilizing ion source assisted magnetron sputtering system (ISAMSS). The surface roughness and crystallite size of the Pt-Ir and Ni-Ir coatings were analyzed by atomic force microscopy (AFM) and X-ray diffraction (XRD), respectively. In addition, coatings were soaked at 700 degrees C and maintained 10 min under N(2) atmosphere using a glass-molding machine. The annealed coatings for oxidation test were examined by energy dispersive X-ray spectrometry (EDS) and for microhardness and reduced modulus test were evaluated by nanoindentation instrucment. The cross-sectional structures between the Pt-Ir and Ni-Ir coating layer and substrates were also examined by field emission scanning electron microscope (FESEM). The results show that surface roughness Ra from 1.25 nm to 3.426 nm was observed with increasing the Ni elements. However, the Ra is less than 2 nm measured in Ir-based coatings doped with Pt concentrations under this study. With increasing Pt and Ni doping, the microhardness of both coatings decreased significantly and the values of reduced modulus of Pt-Ir alloys are larger than that of Ni-Ir alloys. After oxidation process, the oxygen concentration of Pt-Ir coatings is less than that of Ni-Ir coatings and the Pt-Ir coatings exhibit superior properties including oxidation resistance, low surface roughness and high reduced modulus over Ni-Ir coatings, especially for the high Pt concentration coatings such as Pt-Ir 2 (55.25 at.% Pt) and Pt-Ir 3 (79.42 at.% Pt) coatings. The surface roughnesses of all specimens annealed at 700 degrees C were slightly larger than as-deposited coatings. Moreover, due to the serious oxidation occurred in Ni-Ir 3 (73.45 at.% Ni) coatings, the value of reduced modulus of this specimen coating is the lowest and the corrsponding Ra value is the largest compared with the rest of Ir-based coatings in the oxidation testing.
Optical imaging with spectrum aberration correction using a filtering macrolens
(2013-07-20)
Lin, Yu-Hsuan
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Lai, Jyun-Yi
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Tsai, Hsin-Yi
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Chang, Han-Chao
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Huang, Hung Ji
A filtering macrolens was developed to simultaneously achieve macro-optical imaging and correct spectrum aberration. The macrolens was a doublet lens comprising a filtering lens and a close-up lens. The shape of the filtering lens was designed to eliminate the optical path differences between the light rays in the absorbing medium. The close-up lens was designed to decrease the effective focal length of an ordinary camera lens to provide high magnification capability and collimate the diverging beams through the filtering lens. Experimental results demonstrated that the spectrum uniformity of the macro-optical images was markedly improved by the filtering macrolens. This innovation may be used in finite conjugate optical systems. (C) 2013 Optical Society of America
Surface wettability of silicon substrates enhanced by laser ablation
(2010-11-01)
Tseng, Shih-Feng
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Hsiao, Wen-Tse
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Chen, Ming-Fei
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Huang, Kuo-Cheng
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Hsiao, Sheng-Yi
Laser-ablation techniques have been widely applied for removing material from a solid surface using a laser-beam irradiating apparatus. This paper presents a surface-texturing technique to create rough patterns on a silicon substrate using a pulsed Nd:YAG laser system. The different degrees of microstructure and surface roughness were adjusted by the laser fluence and laser pulse duration. A scanning electron microscope (SEM) and a 3D confocal laser-scanning microscope are used to measure the surface micrograph and roughness of the patterns, respectively. The contact angle variations between droplets on the textured surface were measured using an FTA 188 video contact angle analyzer. The results indicate that increasing the values of laser fluence and laser pulse duration pushes more molten slag piled around these patterns to create micro-sized craters and leads to an increase in the crater height and surface roughness. A typical example of a droplet on a laser-textured surface shows that the droplet spreads very quickly and almost disappears within 0.5167 s, compared to a contact angle of 47.9A degrees on an untextured surface. This processing technique can also be applied to fabricating Si solar panels to increase the absorption efficiency of light.
Surface wettability of silicon substrates enhanced by laser ablation
(2010-11-01)
Tseng, Shih-Feng
;
Hsiao, Wen-Tse
;
Chen, Ming-Fei
;
Huang, Kuo-Cheng
;
Hsiao, Sheng-Yi
Laser-ablation techniques have been widely applied for removing material from a solid surface using a laser-beam irradiating apparatus. This paper presents a surface-texturing technique to create rough patterns on a silicon substrate using a pulsed Nd:YAG laser system. The different degrees of microstructure and surface roughness were adjusted by the laser fluence and laser pulse duration. A scanning electron microscope (SEM) and a 3D confocal laser-scanning microscope are used to measure the surface micrograph and roughness of the patterns, respectively. The contact angle variations between droplets on the textured surface were measured using an FTA 188 video contact angle analyzer. The results indicate that increasing the values of laser fluence and laser pulse duration pushes more molten slag piled around these patterns to create micro-sized craters and leads to an increase in the crater height and surface roughness. A typical example of a droplet on a laser-textured surface shows that the droplet spreads very quickly and almost disappears within 0.5167 s, compared to a contact angle of 47.9A degrees on an untextured surface. This processing technique can also be applied to fabricating Si solar panels to increase the absorption efficiency of light.
The Glass-Molding Process for Planar-Integrated Micro-Optical Component
(2011-01-01)
Huang, Chien-Yao
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Sze, Jyh-Rou
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Huang, Kuo-Cheng
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Kuo, Chao-Hui
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Tseng, Shih-Feng
This paper presents a precision glass-molding process to fabricate planar-integrated micro-optical components (PIMOC) applied to a micro projection display system, optical interconnection system and optical storage system. The PIMOC was designed based on wave propagation theory, and fabricated using a glass molding process. Experimental results are discussed in this article. The experiment showed that the PIMOC fabricated in a vacuum environment meets the design value with precision glass-molding technology (PGMT) at a molding force of 2.75 kN, a molding temperature of 750 degrees C and a cooling rate of 49 degrees C/min. (C) 2011 The Japan Society of Applied Physics