Search

A high precision Micro-CMM (Coordinate measuring machine) is introduced for the 3D measurement of part dimensions in meso to micro scale. Expected measuring range is 20×20×10 mm and the resolution is 1 nm. In order to enhance the structural accuracy, some new ideas are integrated into the design, such as the semi-circular shape bridge for better stiffness and the co-planar stage for less Abbé error. The ultrasonic motor and linear diffraction grating interferometer are used to drive the stage and feedback the position to the control. Some problems due to current techniques are also addressed. [ABSTRACT FROM AUTHOR]

Conventional levels are employed to measure just one dimensional inclinations each time, and are frequently used to measure inclination, straightness and flatness. There are two disadvantages when such levels are used to measure two dimensional inclinations (such as flatness): (1) two measurement steps are needed to measure two orthogonal directions in flatness; and (2) the two directions cannot be perfectly perpendicular to each other because of setting errors. This paper describes the development of a diffraction optoelectronic level which employs 1 pendulum, 1 1D reflection grating, 1 reflection mirror, 1 2D PSD and 1 laser diode. In this system, the laser light projected onto the reflection grating which is fixed on the pendulum, and the +1 order diffraction light ray of reflection grating was reflected to 2 dimensional position sensing detector (2D PSD) by the first surface mirror. The laser diode, first surface mirror, 2D PSD and pendulum are fixed on a fixture. Thus, the inclination measurement result can be obtained from the output of the PSD. A novel system was established and proven in experiments. The measurement range of rotation along x-axis and rotation along y-axis are ±4000 arc sec and ±4000 arc sec respectively. The accuracy of them are about ±1.2 arc sec and ±1.0 arc sec respectively. [ABSTRACT FROM AUTHOR]

With advances in micro fuel cell development, the production of hydrogen for micro reformer has become increasingly important. However, some problems regarding the micro reformer are yet to be resolved. These include reducing the size, reducing the quantity of CO and combining the fuel cell, among others. Accordingly, in this investigation, array micro temperature sensors and heaters are combined within a silicon-based micro reformer to measure and control the temperature and thus improve performance and minimize the concentration of CO. In this work, micro-electro-mechanical-systems (MEMS) of the micro channel type are fabricated on a silicon substrate to enhance the methanol conversion ratio. Array micro temperature sensors and heaters are made of platinum and placed inside the micro reformer. Although the micro temperature sensor and heater have already been used to measure and control temperature in numerous fields, they have not been employed in micro reformer and commercial products. Therefore, this study presents a new approach for combining array micro temperature sensors and heaters within a silicon-based micro reformer to minimize the size and improve performance. [ABSTRACT FROM AUTHOR]

An intelligent remote monitoring system based on Windows CE OS is developed in this research. It includes an embedded OS, a remote monitoring system, a Bluetooth interface and an intelligent agent. With the characteristics of the embedded system, the developed monitoring system requires less resources than general high-end monitoring system. The system has hard real-time (1 ms) function for monitoring the disorder of machine. In addition, Bluetooth wireless technology plays an important role for remote message communication and connection between different neighbourhood machines. For monitoring, several intelligent agents are designed to judge if there is any anomaly of machines. The intelligent agents can also search and locate the position of the equipment engineer. Then, the monitoring messages will be transmitted to the equipment engineer. [ABSTRACT FROM AUTHOR]

Since the Laser alloying process system has nonlinear coupling and time varying dynamic characteristics, it is very difficult to establish an accurate process model for designing model-based controller. Hence, an adaptive radial basis function sliding-mode control is proposed by combining the advantages of adaptive neural network and sliding-mode control strategies. It has on-line learning ability to deal with the system's nonlinear and time-varying uncertainties by adjusting the control parameters. Two adaptive radial basis function sliding-mode controllers are designed for tuning the Laser power and the traverse velocity simultaneously to tackle the absorptivtiy and geometrical variations of the work pieces. The simulation results show that the good surface lapping performance is achieved by using this intelligent control strategy. [ABSTRACT FROM AUTHOR]

It is necessary and important to find the focal plane in order to locate where the interference fringe is, and to determine the vertical-scan range prior to the scanning operation for an SWLI. A novel scheme is proposed in this paper for simultaneously carrying out the auto-focusing and the real-time 2-D measurement. Conventionally in a SWLI, it always happens that the interference fringe appears across the focal plane, and therefore the in-focus image is blurred by the interference fringe, which makes it difficult to carry out the auto-focusing and the 2- D measurement with the in-focus image. A multi-function SWLI has been developed such that the 2-D and 3-D measurements can be done simultaneously. Although the 3-D profile reconstruction is basic to an SWLI, the real-time 2-D measurement is not trivial. The proposed scheme is based on clarifying the out-of-focus images where interference fringes do not exist. The proposed scheme is applied on some preliminary experiments and it shows that the real-time 2-D measurement can be realized, and moreover, the accuracy of the 3-D profile reconstruction can also be improved. [ABSTRACT FROM AUTHOR]

The precision measurement of a lens wedge and decenter is badly needed in the optical testing of the imaging lens production. The three point reference plane measurement method was introduced. We do the evaluation of the wedge and tilt measurement of the aspheric lens by Panasonic UA3P. [ABSTRACT FROM AUTHOR]

Automatic optical inspection equipment in Asiapacific region market has grown rapidly in recent years. In this paper, an industrial FPC application of automated optical inspection system is presented. An illumination delivers high intensity and uniform lighting. A flat vacuum table applys sufficient suction to overcome panel warping. The processor of the system receives the images and software algorithms to analyze the acquired image. The false alarm rate of the system is less than 10%. [ABSTRACT FROM AUTHOR]

This study employs the commercial DEFORM™ 3D finite element analysis software to simulate superplastic blow-forming of titanium alloy (Ti-6Al-4V) sheet in an ellip-cylindrical die. The titanium sheet is assumed to be a rigid-plastic material with homogeneous and isotropic properties. The model of the ellip-cylindrical die and titanium sheet is constructed using three-dimensional solid elements. Simulations are performed to investigate the effects of shear friction, sheet temperature, die height and length of the die's short axis on the thickness, effective stress, effective strain and critical damage characteristics of the formed sheet. The Taguchi method is then applied to optimize the processing parameters for the superplastic blow-forming process such that the thickness of the formed titanium sheet is optimal average distribution. The simulation results confirm the effectiveness of the Taguchi method in identifying the optimal blow-forming processing parameters for the current Ti-6Al-4V titanium alloy sheet. [ABSTRACT FROM AUTHOR]

We have designed a phone lens module of compact size which is less than 5 mm thick and has an excellent image performance. For cost and production considerations, plastic lenses instead of glass/plastic hybrid or all glass design are chosen. The sensor pixel size is 1.75 um, resolution limit are 280 lp/mm for Nyquist frequency and 140 lp/mm for Black/White and full color images respectively. The resolution performance (MTF, modulation transfer function) of this design can reach 50% or higher at half of Nyquist frequency within 90% image field. The RMS wavefront error is also less than 0.2 at all field. TV distortion is only 0.2%. [ABSTRACT FROM AUTHOR]

Techniques for performing uniform and high brightness is very important for TFTLCD display. The backlight module with light guide plate (LGP) is the key to achieve uniform and high brightness. Surface modification on light guide plate (LGP) can enhance the brightness and uniformity of TFTLCD display. A novel design, which integrates the merits of diffraction optics and forming technology, is proposed in this research for the higher brightness of LGP. A light guide plate with diffraction grating has been designed. The light emitting surface has a plurality of diffraction grating units. Each diffraction grating unit has a strong diffraction portion and a weak diffraction portion. They are orthogonal each other. Area ratios of the strong diffractive portions in the diffraction grating units proportionally increase with increasing distance away from the light incident surface. Two LGP designs with diffraction optics have been demonstrated. One is for large size TFTLCD displays with CCFL as the light source. Another one is small size TFTLCD displays with LEDs as the light source. Both designs with diffraction optics on LGP can increase the overall efficiency of utilization of light with high brightness and uniformity. [ABSTRACT FROM AUTHOR]

Melting and recrystallization phenomena of plasma-enhanced chemical vapor deposition (PECVD) of amorphous silicon (a-Si) thin films for both frontside and backside excimer laser crystallization (ELC) have been investigated by in-situ realtime optical reflectivity and transmissivity (TRORT) measurements with nanosecond time resolution. The longest melt-phase duration of 90-nm-thick a-Si thin films for both frontside and backside ELC is 350 ns. The ablation excimer laser fluence of a-Si thin films for frontside ELC is higher than that of backside ELC because SiO2 films show anti-reflectivity for excimer laser beam. TRORT measurements reveal that the solidification direction of molten Si for both frontside and backside ELC start from the interface of the sample and the recrystallization mechanism for both frontside and backside ELC are the same. [ABSTRACT FROM AUTHOR]

The structure and properties of electroless Ni-P and Ni-Mo-P alloys, including the as-plated and annealed deposits, on the aluminum alloy 5052, have been investigated to evaluate the corrosion resistance, thermal stability, electric conductivity, and mechanical characteristics of the coating assemblies. The corrosion behavior of the obtained deposits was examined in a 0.5M H2SO4 environment. The crystal structure of the electroless Ni-based alloys was analyzed by X-ray diffraction (XRD), and the surface morphology and microstructure of Ni-P and Ni-Mo-P alloys were examined by field emission scanning electron microscopy (FE-SEM). The experimental results indicate that the corrosion rate of the Ni-Mo-P coating produced at 70°C and pH 7.0 is almost equals that of the Ni-P film in a 0.5M H2SO4 environment. It is also found that the Ni-Mo-P ternary alloy reveal excellent thermal stability after annealing at 400°C for 1 hr. The electroless Ni-Mo-P deposits have a potential to apply to precision mould and surface metallization of substrates, based on the excellent performance of the ternary alloys. [ABSTRACT FROM AUTHOR]

In this study, the optical multilayer thin-film coatings, started from optical design, are successfully deposited on glass substrates. Thermal evaporation method is used to prepare optical multilayer thin-film coatings, such as band-pass filter, edge filter, anti-reflective coating, for key components of consumer electronics products. Electron beam gun evaporation with and without plasma-ion enhanced source during deposition are compared in our system. The coating products, deposited with plasma-ion enhanced source, have high packing density, high refractive index, good adhesion, in comparison to those of conventional thermal evaporation or electron beam gun evaporation without plasma-enhanced source in coating chamber. In addition, excellent environmental stability, impervious to humidity, good uniformity among the substrate, and low wavelength shift with temperature in coating layers, which are especially important for mass prodution, are sucessfully obtained in this study. [ABSTRACT FROM AUTHOR]

Surface Plasmon Resonance (SPR) is a powerful technique to detect biomolecular interactions such as DNA and DNA, RNA and protein, antigen and antibody interactions in real-time. The change of SPR situation can be measured by angle, wavelength, intensity or phase interrogation. Since a first commercial SPR instrument was presented at 1990 by Biacore life sciences, there were many different types of SPR instruments bulit. We propose an SPR instrument which adds imaging function to intensity interrogation and can be applied in array chip observation. The wavelength interrogation function also integrated in this instrument. This instrument can be used to detect biomolecular interactions in real time and produce sensorgram. For preliminary experiment, we used different concentration rabbit IgG and Anti-IgG to verify our instrument design, and the experimental results are shown as sensorgram. Optical detection limit at intensity interrogation and wavelength interrogation of the instrument has achieved 8×10−4 RI/° and 4×10−4 RI/nm. [ABSTRACT FROM AUTHOR]

The purpose of this research is to manufacture a new small-tipped stylus for measurement of micro machine elements with concave shapes. It is very difficult to measure surfaces of concave shapes because its overhanging part becomes the obstacle against measurement. We need to develop a small tipped stylus to be able to reach the position to be measured. In machining process, one of the photolithography technique is applied: the combination of the electron-beam exposure and the etching process of a silicon chip. In this paper, a preferable stylus shape is proposed and the trial manufacturing of the stylus has been performed with wet etching and dry deep reactive ion etching (DRIE). Several process conditions of etching and resultant shapes of manufactured styli are investigated and evaluated with SEM observation. The difficulty of achieving adequate etched features is shown especially due to the degree of under-etch phenomena. [ABSTRACT FROM AUTHOR]

In this paper, we synthesized single-walled carbon nanotubes (SWCNTs) using chemical vapor deposition (CVD) process in a furnace with three different heating regions. Ferritin nanoparticles were used as catalyst for the CNTs synthesis through carbon source which are methane and ethylene mixture. The reason we used a three stage furnace is to preheat the carbon source at higher temperatures and to synthesize CNTs at lower temperatures. This method can be effective to grow SWNTs at lower temperature. Furnace temperature, methane flow, productivity of CNTs and the diameter distributions of CNTs were considered in the process of CNTs synthesis. The lowest synthesis temperature of CNTs grown from ferritin nanoparticles was 700°C. In the future, it is possible to apply this method to grow CNTs on electronic devices at the lower temperature. [ABSTRACT FROM AUTHOR]