Papers by Keyword: Mask

Abstract: Commercial planar power transformer core majorly inserted manually as stand-alone components sandwiched on the stacked multilayer PCB of the power supply system. The indispensible gap within the layers still seems to produce significant losses due to leakage inductance meanwhile the low thermal conductivity of the PCB worsen the generated heat dispersion process. Thus this paper is to explore a new approach in order to attain a higher efficiency, high thermal conductivity dispersion and low cost mass production on this magnetic device using CMOS development procedure on a silicon wafer substrate. Considerations for the optimum mask design process for power transformer based pattern micromachining on the Silicon substrate process using low cost wet etching process are presented and discussed. The process are to manipule the anisotropy properties using concave and convex mask pattern to produce a correct final angle and pattern using recognized KOH solutions optimized ratio. The conventional wet etching concept has been explored with a several mask design template and comparison between several pattern size in order to attain the best fine structure and correct angle pattern up to 100 um depth. Several convex corner corners compensation methods has been reviewed which finally concluded to method proposed by Wei Fan and Dacheng Zhang has been verified within the 40% KOH:IPA in 50°C solutions experiment.

Abstract: A new method based on image patch reordering for removing salt-and-pepper noise from corrupted images is presented. Firstly, the problem of salt-and-pepper noise removal can be turned into the problem of image in-painting. Then, we can use the image patch reordering method to recover the missing pixels and fulfill the salt-and-pepper noise removal. Experimental results demonstrate that the proposed method obtain much better performance in terms of both qualitative and quantitative assessment. Especially, the proposed method provides the improvement in the performance of noise suppression and detail preservation.

Abstract: With the demand of high-quality and aesthetical products in the domain of medical microbiology, it’s more and more important to join micro weld. Due to traditional joining methods’ difficulty in meeting the demands, laser transmission micro-joining is of great significance. The materials used to laser transmission micro-joining based on the mask are PET, and the experiments are conducted on diode laser. The weld geometry with different gap widths on the mask is demonstrated at the same process parameters. In addition, the causes of forming different morphologies are analyzed. The formation mechanism of weld is analyzed as well. Moreover, process parameters’ effects on joint strength and joint width are deeply explored when gap width on the mask is 0.3mm. The results show that100 um micro weld joint is realized. At the same time, the range of process parameters is determined.

Abstract: This article uses semiconductor laser for mask assisted laser transmission micro joining PET and PET with clear weld absorbents, the mask slit width is 0.3mm, using CCD to plan experimental design. The mathematical model of joining process parameters with joint strength and joint width was established using response surface methodology. Experimental verification was also done. The actual joint width was compared to mask slit width and the process parameters were optimized. The results show that the mathematical model can response the relationship between process parameters and joining quality, the mask can effectively control the joint width, reasonable process parameters can obtain high-precision, high-intensity joining quality.

Abstract: Cost of silicon carbide (SiC) wafer has been improved owing to the development of larger and higher quality wafer technologies, while the process stays long and complicated. In this paper, we propose a novel short process of ion implantation and provide the fabrication model SiC schottky barrier diodes (SiC-SBDs) devices. Currently common mask layer of ion implantation employs high heat resistant materials such as metal oxides. Because the ion is implanted to SiC wafer at high temperature between 300 °C and 800 °C due to avoid the damage of SiC crystal structure. The process using oxide layer tends to became long and complicated. On the other hand, our proposal process uses a heat resistant photoresist material as the mask instead of the oxide layer. The heat resistant photoresist is applied to newly developed SP-D1000 produced by Toray Industries, Inc.. We demonstrated to fabricate model SiC-SBDs devices based on our proposal process with SP-D1000 and confirmed the device working as same as a current process.

Abstract: MOS capacitor devices based on silicon carbide (SiC) are largely used as hydrogen detectors in high temperature and chemically reactive environments. A SiC MOS capacitor structure used as hydrogen sensor is analyzed by extensive simulations. The sensitivity to hydrogen detection, stability to temperature variation and dependence on interface states concentration are evaluated. The effects of structure parameters on sensors performance are also investigated. Results show that the oxide layer type and thickness and the SiC polytype have a significant influence on the detectors performance. The proposed optimum structure for high temperature hydrogen detection is based on 3C-SiC substrate and 10nm TiO₂ layer. In accordance with the simulations results, three types of masks are designed for the fabrication of SiC MOS capacitor structures.

Abstract: The characterization of surface wear resistance of materials usually relies on the measurement of slight wear. There are two obvious shortcomings for weighing method. In order to improve the measurement accuracy, a more intuitive and reliable method for quantitative measurement of slight wear, interference microscope method, has be given. Higher accuracy (the order of micrometer) can be achieved using the interferometry for the measurement of slight wear. The results show that the masking processing technology can ensure that all samples for wear testing and other analysis are obtained under the same pretreatment conditions and vacuum processing conditions, speed up the commercialization of processing technology, and comparing the cross-sectional areas of wear scars is a correct way to characterize the wear resistance of different zones.

Abstract: Metal workpiece was processed by nanosecond pulsed laser electrochemical micro-etching with masks patterns in the shape of letter "E". In the experimental system established, the effect of different laser energy on processing quality was studied in air. In the different concentrations of the electrolyte, through optimized composite machining parameters, machining results of different laser energy with the masks were analyzed and compared in Aluminum alloy and Stainless steel. There was a large of difference in machining morphology by laser electrochemical micromachining with masks in two different metal materials. The results show that laser electrochemical micro-etching with masks has high efficiency and the prospects for the large-scale production, but the etching precision should be also further improved. Moreover, the nanosecond pulsed laser thermal-stress etching, electrochemical etching and the two combined coupling etching are the main factors to achieve the metal removal.

Abstract: AES encryption system is briefly introduced, the function and principle of mask technology has been expressed. Because the vulnerability of the AES encryption system by the energy attacks, the measures need to add to increase the ability of energy analysis of AES. The mask design content is added in the AES encryption system. The mask design of AES encryption was given detailed. Four steps of the mask design process are also given. The conversions and implementation of AES mask design are presented, such as, the transformation of S box and so on. The implementation methods of how to eliminate the mask are given in the final round of AES encryption. It is finally discussed that threaten and influence of energy attack on AES.

Abstract: This paper introduces the preparation method of large scale free P+ diaphragm based on the boron doped and anisotropic wet etching techniques. It also explores the impact of the RF power configuration, pressure and SF6 flow rate on etching rate during ICP etching. It is indicated that silicon can be used as mask to solve the problems of large scale film break and the adhesion between mask and film which are caused by vacuumization during ICP etching. In order to avoid over etching, twice etching technique can be employed to control etching time and end point. Results of the experiment show that through etching, free P+ diaphragm can be fabricated into sensitive free beam which can be widely used in MEMS.