Chih-Chung Yang

Deep Dry Etching Patterned Silicon Using GeSbSnOx Thermal Lithography Photoresist

An innovative chemical composition GeSbSnOx is introduced as positive-type photo-resist in sub-micro scale lithography. Unlike the conventional acrylic type photo-resist, this innovative photo-resistor can overcome the diffraction limit using the thermal mode recording and leave a small hole diameter of 350 nm on the surface under this experimental condition. The effects of the reactive ion etching parameter on the silicon etching were reported. The major etching parameters include passivated time, etching time, passivation cycles, total worked backing pressure, platen power, coil power and passivation gases applied. The etched depth increased monotonically with increasing the gas pressures and the platen powers. The most important factors to reduce the reaming effect of Si etching are found to be the ratio of passivation time to etching time and the etching gas flow rate. Both etched depth and reamed width decreased with increasing the ratio of passivation time to etching time and the linear relation was observed between the etched depth and the ratio.

Bonding PDMS Microfluidic Devices to PMMA and Glass Substrate Using Pulsed UV Laser Technology

This study presents a new method for surface modification of polymeric materials by using pulsed UV laser welding technology. The bonding procedures including ablation treatment, Oxygen plasma treatment, adhesive layer bonding and cured by pulsed UV laser writing system was exhibited. The investigation of various parameters for UV laser writing system was performed and discussed by using water contact angle measurement. This technique has been successfully applied to bond dissimilar polymer substrates (polydimethylsiloxane (PDMS) to polymethylmethacrylate (PMMA)). The scanning electron microscopy (SEM) image reveals clearly that there was no clogging in the microchannel or deformation observed between PDMS and PMMA. The method was straightforward and the integrity of microfluidic features was successfully preserved after bonding.

Surface Formation of Nano- / Micro- Structures on Titanium Alloy Composites using Picosecond Laser Scanning Technology

This study reports on the development of picosecond laser system to titanium alloy surface treatment applications. In the picosecond laser-scanning system, that is based on the fiber-optics laser source and integrated with a designed optics / optical machine design and control technology of scanning system. To analyze the laser material interaction, the laser fluence, pulse repetition frequency of laser source, position of focused points, scan speed and pulse duration were adjusted. After laser surface treatment, the surface roughness and surface morphologies of treated surface were evaluated by using a field emission scanning electron microscope. Moreover, the contact angle measurement was used to analyze the hydrophilic and hydrophobic properties of the treatment surface with micro/ nanostructures.

Laser Drilling of a 7-layer Flexible Printed Circuit Board using a Pulsed Ytterbium Fiber Laser System

Recently, laser-processing industry is becoming increasingly popular because of its advantages of low cost, fast and good energy efficiency. The electric circuit board manufacturers also began to import related laser processing technology to improve the productivity. This paper presents the laser drilling process and quality analysis of the 7-layer flexible printed circuit (FPCB). A laser drilling system pulsed Ytterbium fiber laser, expander device, focal lens, galvanometric scanner and XY-axis manual stage was used to perform the hole cutting of the multilayer-layer FPCB. This study succeeded in establishing a comparing procedure, which enabled the characteristic comparison between the various experimental conditions. We believe that this study provides a useful database for FPCB drilling technology.

Laser Micro-Structuring on Glass Substrates with Compensation Function for Multi-wavelength Mixed Laser Diode Module

A glass substrate has excellent optical transmittance for the visible spectrum (400–700 nm). This study used three type glass (D263TTM, EAGLE XG○,R, and BK7) for laser micro-structuring in the light compensation technique applied to a multi-wavelength mixed light module. An ultraviolet laser system combined with a high-speed galvanometric scanner was used to fabricate microstructures on the specimen surface. The light compensation chromaticity properties of the microstructures on glass substrates depended on the laser machining conditions. The characteristics of the machined glass were systematically analyzed using a spectrophotometer and charge-coupled device camera. The experimental results demonstrate that the microstructures affected chromaticity under different laser micro-structuring pitches.

Parameters optimization of laser electrode patterning on ITO/glass using multi-performance characteristics analysis

The objective of this study was to obtain the optimal parameters for laser electrode patterning of indium-tinoxide (ITO) films coated on soda lime glass substrates; the parameters were determined through grey relational analysis. The electrode patterning parameters affecting the sheet resistance and optical transmittance of the film include the laser power, pulse repetition frequency, pulse duration, and focus point position. Multiple performance characteristics associated with the sheet resistance and optical transmittance were investigated by conducting experiments. An infrared (1064 nm) laser system was used to directly fabricate electrode patterns on ITO films, and the characteristics of the patterned films were systematically analyzed using an ultraviolet-visible-near-infrared spectrophotometer and a four-point probe instrument. The data obtained from the experiments were analyzed to optimize the laser patterning parameters correlated with multiple performance characteristics.

The field of view and resolution of marco images enhanced by modified superresolution method

The properties of the image acquired from a general camera contain a large field of view (FOV) and low resolution. In contrast, the microscopy usually offers higher magnification image a smaller FOV but high resolution. This study attempts to develop a modified super resolution (MSR) method to obtain both of high resolution and large FOV properties for criminal identified microscopic images. The MSR method can analysis the images pixels either from the intensity of single point (ISP) or the intensity of neighbor point (INP), when a microscopic image (150X) captured under white light, and three macro images (60X) captured under three different wavelength lights (red-620nm, green-520nm and blue-460nm), and then can reconstruct a new criminal identified image with high resolution and large FOV. Finally the simulated experiments in an ant model show that, the ISP analysis offers a reconstructed image with higher contrast and identification degree, synchronously the INP analysis affords an image has smoother edge.