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1st International Conference on Information Science and Engineering, ICISE2009

作者： Chen, Guanghua Liu, Ming Zhu, Jingming Zheng, Weifeng School of Mechatronics Engineering and Automation Shanghai Key Laboratory of Power Station Automation Technology Shanghai University Shanghai 200072 China Key Laboratory of Advanced Display and System Applications Microelectronic Research and Development Center Shanghai University Shanghai 200072 China

ISBN: (纸本)9780769538877

An improved modular multiplication algorithm based on the interleaved multiplication is presented in this paper. Carry save addition (CSA), redundant representation, a fast lookup table and a counter register are used to improve this algorithm. Carry save addition and redundant representation are used to replace other additions like carry select addition, carry lookahead addition and so on, because carry propagation brought by those additions can be prevented by carry save addition, and redundant representation can make the arithmetic operations fast without carry propagation. The fast lookup table with only 7 pre-calculated values can minimize the number of additions, and can only be addressed once in one iteration, which not only speed up, but also save area compared with other literatures used lookup tables. The iteration number can be reduced by a counter register being added in this improved method to compute the number of 0 from the most significant bit of one operand like X. Analysis and emulation result shows the area and time complexity (AT) of the improved method is equal or even less than 2n2. ©2009 IEEE.

关键词： Table lookup

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Global motion estimation for moving object extraction in MPEG video streams

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Journal of Information and Computational Science 2009年第1期6卷 341-350页

作者： Yang, Gaobo Zhou, Qiya Zhang, Zhaoyang College of Computer and Communication Hunan University Changsha 410082 China Key Lab. of Advanced Display and System Applications Shanghai University Shanghai 200072 China

In this paper, a novel moving object extraction scheme for MPEG video stream is proposed. Firstly, the DC and AC [1], AC [8] coefficients are extracted directly from MPEG video stream to re-construct the DC + 2AC image, which is used to obtain the contour feature of I frame. Secondly, the sparse motion vector field of P frame is interpolated to make it dense and then projected to I frame iteratively. Moving object is extracted by the fusion of spatio-temporal segmentation. The innovation lies in the global motion estimation (GME) algorithm in compressed domain to compensate the global motion caused by camera. Thus, the proposed approach is feasible for almost any sequence including the static scene and the dynamic scene. Since only the background blocks are used to estimate the motion parameters, the computational complexity is greatly reduced. Experimental results demonstrate that the proposed approach can obtain satisfactory segmentation results and can be used in real-time system because it is mainly implemented in the compressed domain. © 2009 Binary Information Press.

关键词： Real time systems

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Compressed sensing based channel estimation for fast fading OFDM systems

引用

Chinese Journal of systems Engineering and Electronics 2010年第4期000卷

作者： Xiaoping Zhou Yong Fang Min Wang Key Laboratory of Specialty Fiber Optics and Optical Access Networks School of Communication and Information EngineeringShanghai University Shanghai 200072 P. R. China Key Laboratory of Specialty Fiber Optics and Optical Access Networks School of Communication and Information EngineeringShanghai University Shanghai 200072 P. R. China Key Laboratory of Advanced Display and System Applications Shanghai 200072 P. R. China

A compressed sensing (CS) based channel estima-tion algorithm is proposed by using the delay-Doppler sparsity of the fast fading channel. A compressive basis expansion chan-nel model with sparsity in both time and frequency domains is given. The pilots in accordance with a novel random pilot ma-trix in both time and frequency domains are sent to measure the delay-Doppler sparsity channel. The relatively nonzero channel coefficients are tracked by random pilots at a sampling rate signifi-cantly below the Nyquist rate. The sparsity channels are estimated from a very limited number of channel measurements by the basis pursuit algorithm. The proposed algorithm can effectively improve the channel estimation performance when the number of pilot sym-bols is reduced with improvement of throughput efficiency.

关键词： compressed sensing sparse channel channel esti-mation fast fading

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Design of RKE system Based on KEELOQ Encryption Technology

Design of RKE System Based on KEELOQ Encryption Technology

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International Conference on Artificial Intelligence and Computational Intelligence (AICI)

作者： Yue-li Hu Yan Zhang Bin Sun Key Laboratory of Advanced Display and System Applications Ministry of Education Shanghai University Shanghai China Shanghai University Shanghai Shanghai CN

KEELOQ code hopping technology is a nonlinear anti-encryption algorithm designed for secure Remote keyless Entry (RKE) systems. It combines a 66-bits transmission length, so as to prevent the system from code predicting, code grabbing and code scanning. Because of its feature of high-security, it effectively overcomes the disadvantages of the traditional fixed code technology. This paper researched on KEELOQ encryption algorithm and presented a designed RKE system based on KEELOQ technology. When the software and hardware were designed, the whole RKE system was afterwards made as a prototype for the functionality tests. The experimental results showed that the design achieved the anticipative effects.

关键词： Cryptography Decoding Information security Counting circuits Automation laboratories Algorithm design and analysis NIST Data security Manufacturing

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Modeling of heat transfer performance for an array of micro jets impinging upon dimpled surface

Modeling of heat transfer performance for an array of micro ...

引用

International Conference on (ICEPT) Electronic Packaging Technology

作者： Tian-yi Geng Jing-yu Fan Yan Zhang Shun Wang Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai China Key Laboratory of Advanced Display and System Applications Shanghai University Shanghai China

The present paper paid particular attention to the flow and heat transfer performance for an array of micro jets impinging upon the dimpled surface by means of CFD modeling. The modeling of a three-by-four jet array impinging upon the smooth, concave- and convex-dimpled surfaces was carried out based on the solution of the steady, incompressible and three-dimensional RANS and energy equations by employing the RNG k-epsiv turbulence model. It has been demonstrated from the present study that the heat transfer performance for an array of the micro jets impinging onto the concave- or convex-dimpled surfaces tends to be somewhat attenuated or augmented in the impingement region, respectively, as compared with that onto the smooth one. And the variational trend with respect to the Nusselt number distribution in the inter-jet region appears to be inconsistent with that in the impingement region. In addition, the flow pattern and primary mechanism by which the smooth, concave- and convex-dimpled surfaces significantly affect the flow field and heat transfer are analyzed and discussed.

关键词： Heat transfer Heat sinks Rough surfaces Surface roughness Microstructure Microchannel Temperature Thermal stresses Electronics cooling Geometry

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Studies on microstructure of Epoxy Molding Compound (EMC)-leadframe interface after environmental aging

Studies on microstructure of Epoxy Molding Compound (EMC)-le...

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2009 International Conference on Electronic Packaging Technology and High Density Packaging, ICEPT-HDP 2009

作者： Xiuzhen, Lu Li, Xu Huaxiang, Lai Xinyu, Du Johan, Liu Zhaonian, Cheng Key Laboratory of Advanced Display and System Applications School of Mechatronics Engineering and Automation Shanghai University Shanghai 200072 China Henkel Corporation 15350 Barranca Pkwy Irvine CA 92618 United States SMIT Center and Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology SE-412 96 Gothenburg Sweden

ISBN: (纸本)9781424446599

The Leadframe-Epoxy molding compound (EMC) interface is known to be one of the weakest interfaces in an electronic packaging exhibiting delamination during reliability test. Interfaces of EMC and leadframes with different metal coatings exhibit different failure mode behavior after environmental aging because of the different adhesion strengths. In this paper, the interface microstructure of EMC-leadframes with different metal coatings was studied using Scanning Electron Microscopy (SEM). The leadframes used in this study were copper, copper with Ag coating, Ni coating and Ni/Pd/Au coating. The results of tab pull testing showed the adhesion strength of the EMC/copper leadframe interface was strongest while that of the EMC/leadframe with Ni/Pd/Au coating interface was weakest. Little delamination appeared on the EMC/Cu sample, including the samples after the moisture and reflow treatment. Delamination appeared on the interface of EMC/leadframe with Ag coating after treatment, and serious delamination was found on the interface of EMC/leadframe with Ni coating. The SEM micrographs showed that there were some microcracks between the filler of EMC and the leadframe. ©2009 IEEE.

关键词： Adhesion

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Adhesion behavior between epoxy molding compound and different leadframes in plastic packaging

Adhesion behavior between epoxy molding compound and differe...

引用

2009 International Conference on Electronic Packaging Technology and High Density Packaging, ICEPT-HDP 2009

作者： Li, Xu Xiuzhen, Lu Johan, Liu Xinyu, Du Yan, Zhang Zhaonian, Cheng Key Laboratory of Advanced Display and System Applications School of Mechatronics Engineering and Automation Shanghai University Shanghai 200072 China Henkel Corporation 15350 Barranca Pkwy Irvine CA 92618 United States SMIT Center and Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology SE-412 96 Gothenburg Sweden

ISBN: (纸本)9781424446599

Adhesion has been identified as one of the key elements in solving failure problems in electronic packaging. Understanding and improving the adhesion between epoxy molding compound (EMC) and leadframes is thought to be a key step towards improving package performance. The objective of this work was to study the effect on adhesion behavior and delamination of plastic packages using various metal coated leadframes that had been subjected to preconditions. In this work, the effects of moisture absorption testing and reflow process on the interface adhesion strength of the EMC/metal leadframes were studied. Three kinds of metal coated leadframes were used: copper, silver coated copper and nickel/palladium/gold coated copper. Adhesion strength was measured using the tab pull test. These data were correlated to some extent with the findings of package delamination observed by the C-mode Scanning Acoustic Microscope (C-SAM). Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) were employed to characterize the surface of EMC and metal leadframes after separation along the vertical plane. ©2009 IEEE.

关键词： Adhesion

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Study on moisture behavior in flip chip BGA packages and bake process optimization

Study on moisture behavior in flip chip BGA packages and bak...

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International Conference on (ICEPT) Electronic Packaging Technology

作者： W.Q. Dai Z.K. Hua J.H. Dai E.W. Pang L. Jiang C.Y. Li P. Liao J.H. Zhang Intel Products (Shanghai) Company Limited China Key Laboratory of Advanced Display and System Applications Ministry of Education School of Mechanical & Electronic Engineering and Automation Shanghai University Shanghai China

The lead-free (LF) and halogen-free (HF) ldquogreenrdquo initiatives are driving the advanced packaging manufacturers to develop new generation materials and assembly technologies. However, the moisture related reliability issues become the significant technical challenge to meet stringent reliability and quality standards comparing to the previous Lead and halogen technology. In this study, the moisture absorption and desorption performance of halogen free and lead free material were investigated. The experimental data revealed that after fully baked process there was still some resident moisture which was mainly contained at substrate level. The modeling data of moisture absorption and desorption behavior with 125degC bake comparison was discussed and was fully aligned with experimental data. Moreover, a dasiasoft bakepsila method via Nitrogen and dry air was introduced. In low RH effect test, under 25degC / 60%RH precondition process, all the moisture absorbed for 1100 hours can be removed by dasiasoftpsila bake. This indicates that not only no moisture absorption in low RH environment, but also an additional dasiasoft bakepsila process occurring during the storage time. The results demonstrated that the storage of moisture-sensitive material in the optimized environment is an attractive facility solution which can reduce the risk of popcorn and cracking problems.

关键词： Moisture Flip chip Packaging Environmentally friendly manufacturing techniques Absorption Material storage Hafnium Assembly Nitrogen Testing

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Modeling of nanostructured polymer-metal composite for thermal interface material applications

Modeling of nanostructured polymer-metal composite for therm...

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International Conference on (ICEPT) Electronic Packaging Technology

作者： Zhili Hu Bjorn Carlberg Cong Yue Xingming Guo Johan Liu SMIT Center and BioNano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology Goteborg Sweden Key Laboratory of Advanced Display and System Applications Ministry of Education and SMIT Center School of Mechatronics Engineering and Automation Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai China Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai China Key Laboratory of Advanced Display and System Applications Ministry of Education and SMIT Center School of Mechatronics Engineering and Automation Shanghai University Shanghai China

Previous studies have discovered a unique type of nanostructured polymer-metal composite for thermal interface material with effective thermal conductivity of 8 W/mK. It is a promising result but extensive efforts are still required to further enhance the thermal conductivity. Therefore, this paper will try to help the process with modeling and simulation. Calculations reveal the alignment of the fibers have insignificant influence. Therefore volume percentages of fiber together with mean interface temperature become the dominating parameters of effective thermal conductivities of thermal interface material. Based on this approximation, simulation was taken which showed good results in comparison with experimental data. However, the preferred volume percentage of fibers (33%) was slightly too large according to the surface image of thermal interface material.

关键词： Polymers Composite materials Nanostructured materials Thermal conductivity Electronic packaging thermal management Conducting materials Thermal resistance Thermal management Polyimides Thermal management of electronics

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Effects of the matrix shrinkage and filler hardness on the thermal conductivity of TCA

Effects of the matrix shrinkage and filler hardness on the t...

引用

International Conference on (ICEPT) Electronic Packaging Technology

作者： Cong Yue Yan Zhang Zhili Hu Johan Liu Zhaonian Cheng Key Laboratory of Advanced Display and System Applications Ministry of Education SMIT Center School of Mechatronics Engineering and Automation Shanghai University Shanghai China SMIT Center & Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology Gothenburg Sweden

Thermal conductive adhesives (TCA) have been widely used as the thermal interface material (TIM). The TCA are usually epoxy or silicone based mixtures containing fillers. The epoxy in TCA also applies a pressure on the filler particles as it shrinks during the curing process. This pressure leads to an increase in the contact area between the filler particles and thus improves the thermal conductivity. In our attempt to discover the effect of filler modulus on the contact areas between two particles we constructed a cell model assay. In order to study the different epoxy characteristics, 28 cases were simulated with different mixtures of epoxy and filler. The thermal conductivity of each case was calculated by FEM. When the shrinkage was higher than 1%, TCA with a filler modulus of 83 Gpa (silver) has the largest contact area, which suggests silver has the best TCA performance among the studied materials. Furthermore the viscoelasticity of the epoxy was simulated to evaluate the fully relax time of epoxy and the effect on the thermal conductivity of TCA.

关键词： Thermal conductivity Silver Conductive adhesives Conducting materials Curing Phase change materials Thermal engineering Heat transfer Electrons Temperature

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