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Intrinsic uncertainties of MEMS fabrication processes can severely affect the performance of devices because the tolerance ranges of these processes are relatively large and improvement of process accuracy is very expensive. Therefore, the analysis of fabrication uncertainties and their outcome on a device performance is a vital task before finalizing the design. In this paper, the effects of process inaccuracy on the performance of MEMS tunable capacitors are studied. Design parameters such as dimensions of electrodes and the initial gap between them and the stiffness of supporting beams are considered as random variables. The variation of these parameters within tolerance ranges drastically alters the capacitor's actual response from the desired one and results in low yield. Hence, design optimization with the objective of maximizing yield in early steps becomes very important. An effective method for yield optimization of MEMS capacitors under given fabrication uncertainties is introduced. The method utilizes aspects of the advanced first-order second-moment (AFOSM) reliability method to find a linearized feasible region to estimate the yield. The yield is calculated directly using the joint cumulative distribution function (CDF) over the tolerance box requiring no numerical integration and avoiding computational complexity. The optimal design verified by Monte-Carlo (M-C) simulation exhibits a significant increase in the yield. The main advantage of this method comparing to other design optimization methods is that the proposed method does not change the design topology or fabrication accuracy. It increases the yield by finding the optimum design variables as demonstrated in this paper. 相似文献
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64.
周有利 《数字社区&智能家居》2009,(21)
该文介绍了推板炉计算机控制系统的控制方案及硬件、软件的具体设计。实现了推板炉各温控点采用单独的温控表进行独立控制,一点一表。并且采用热效率自寻优的方法自动调节风煤比,达到了经济燃烧的目的。系统运行表明:本系统大大提高了推板炉炉运行的稳定性、经济性,减轻了操作人员的劳动强度,收到了满意的控制效果。 相似文献
65.
根据梅山钢厂石灰窑现有采用孔板流量计测量煤气流量所存在的问题,提出了一种基于WZ-2188超声波流量检测为基准,结合孔板流量计流量检测的双重检测方法,实现了石灰窑供气系统煤气流量的准确测量,并以此为基础实现煤气流量在线补偿。此补偿方法对于采用孔板流量计测量煤气流量的套筒石灰窑均适用。 相似文献
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Youn‐Gyoung Chang Seong‐Hee Nam Nam‐Kook Kim Yun‐Ho Kook Jinook Kim Soon‐Sung Yoo Chang‐Dong Kim In‐Byeong Kang In‐Jae Chung 《Journal of the Society for Information Display》2009,17(4):301-307
Abstract— Recently, potential breakthrough technologies for low‐cost processing of TFT‐LCDs and new process developments for flexible‐display fabrication have been widely studied. A roll‐printing process using etch‐resist material as a replacement for photolithographic patterning was investigated. The characterization of the properties of patterns formed in roll printing, a method to fabricate cliché plates for fine patterns, and the design of a new formulation for resist printing ink is reported. The pattern position accuracy, which is one of the most important issues for the successful application of printing processes in display manufacturing was studied and how it can be improved by optimizing the blanket roll structure is explained. New design rules for the layout of the thin‐film‐transistor array was derived to improve the compatibility of roll printing. As a result, a prototype 15‐in.‐XGA TFT‐LCD panel was fabricated by using printing processes to replace all the photolithographic patterning steps conventionally used. 相似文献
68.
在日常生活中,肢体残障人士因其身体的种种不便,经常需要别人帮助。开发为残疾人设计的板式家具是让残疾人以最大限度地"自己完成"为设计目标,最大可能地帮助残疾人自己料理生活,提高生活质量。尽量减少照料人员时间和精力,同时还会增加残疾人的自信心,拓展其私人的生活空间。 相似文献
69.
Jong Sung Yoon 《Computer aided design》2008,40(9):905-915
This paper presents a simple and efficient method to approximate a developable surface to a compound design surface by a polynomial. It is required to predict a final shape of roll bending in the fabrication of a curved shell plate. The roll bending process usually makes the cylindrical or conical curvature from an initial flat plate. It means that the final shape is developable or the surface representation has zero Gaussian curvature. The fabrication shape is important in order to estimate process parameters of roller bending.An optimization problem is formulated to determine the polynomial surface which is in the closest proximity to the design surface or the given shell plate, which is subjected to developability. The results and the efficiency of this algorithm are verified and evaluated by applying it to some shell plates which are obtained from a real ship model. The predicted bending shape becomes fundamental information in determining more process parameters for the fabrication of a compound curved shell plate. 相似文献
70.