Advanced Materials Research Vol. 548

Abstract: Electrostatic discharge (ESD) is a single, fast, high current transfer of electrostatic charge between two objects at different electrostatic potentials, and it is one of the most important failure mechanisms in integrated circuits due to their complex operation condition. The modes, mechanism, and models of the ESD failure were discussed. Firstly failure modes of ESD were classified and the failure mechanisms were described. Then three failure models including Wunsch and Bell model, Speakman model and Tasca model were summarized. The differences of the assumption and application area of these models were discussed in detail later. At last, suggestions for future studying ESD physics of failure model were proposed.

Abstract: This paper is to reveal the small crack growth law of 6A02 aluminum alloy specimen by SEM in-situ experiment. The Nisitani H. formula for crack propagation is modified by SEM in-situ experimental results. The effect of corrosion is emphasized in small crack growth law of 6A02 specimen by introducing of corrosive factors. The fitting curve between corrosive factors and corrosive time is revealed. It would provide a theoretical foundation for the corrosion fatigue damage of 6A02 aluminum alloy.

Abstract: A roll barrel breakdown accident took place on CSP mill. After investigating of the accident scene and the roll service condition, analysing the barrel fracture and sampling tests, proved that main cause for the roll breakdown was unusual and there appeared a strip-like crack on the boundary layer resulting from the initial flaws extending along the roll circle direction; furthermore, the flaws caused fatigue breakage along the roll inner cross section, which resulted in the barrel breakdown.

Abstract: A new method of fault diagnosis on the rotating rectifier of aeronautic synchronous is raised in the work. Firstly, the condition, truth and approach of EMD are introduced, and the method and steps of building up the feature vector are also included, Secondly the theories of LS-SVM and the arithmetic in the classification are also included. Finally taking the faults of one and two diodes turning off for example, after extracting the feature vector of exciting current based on EMD and establishing the classifying method based on Gauss RBF LS-SVM, the test, analysis and comparison can be on between LS-SVM and NN the conclusion can be got that the classified method referred in the work owns higher exactness, takes less time and has more application on the on-line fault diagnosis NN.

Abstract: This paper presents a research on skin effect’s influence on the current density distribution of Cu/barrier layer and Cu/cap layer interfaces of copper interconnects’ via vicinities. A two-level Cu-interconnect structure in different positional relationships with the ground plane is discussed. Through the three-dimensional (3D) finite element simulation of the interconnect structure, the variations of current density on three important surface areas are obtained when skin effect is significant, showing that the current density in the three surface areas near the via has been strongly influenced by current crowding and skin effect. So in many cases the influence of skin effect on via top and via bottom failures of Cu interconnects under high frequencies can not be ignored.

Abstract: Aimed at the situation that the welding voltage is easy to be disturbed by the voice outside, median filtering and average filtering are adopted to filtering signal of the voltage the rotating arc sensor collected in this paper. They can make the voltage waveform get obvious improvement. In order to get information which the welding torch deviated the welding seam more accurately, left and right integration, Characteristic Harmonics method and welding torch deviation recognition algorithm are adopted to identify the deviations in this paper. Finally compare the two kinds of identification deviation methods and obtain better welding torch deviated information.

Abstract: The paper proposes a method for the selection of the optimal solution among different feasible solutions of the SHEPWM nonlinear model. The method regards the power losses of the switching devices as a criterion for evaluating the possible groups of solutions. The overall power losses are calculated under each combination of the switching angles at first. The variation track of the power losses that could determine the optimal solution under the specific value of m is presented later. The simulation results contrast the new method with the traditional THD method. A comprehensive evaluation considering both methods was concluded at last.

Abstract: The influence rules of the different parameters on automotive covering stamping forming and springback, such as blank-hold force、friction condition、draw-bead is studied using the FEM simulation software DYNAFORM combined with the elastic and plastic FEM. In practical production process, through reasonable setting of process parameters, the springback is effectively controlled, the quality of the products is improved.

Abstract: In this paper, melting process in a co-rotating twin screw extruder was studied based on two dimensional melting model of flow field cross section. Positive displacement conveying characteristic in the melting section was assumed and melting process of each section was regarded as the result of time evolution. Procedure of melting was analyzed according to experiments and numerical simulations, both indicating that solid materials in the flight zones would melt firstly and carcass wrapped in the middle of melt would be molten finally. Liquid fraction contours showed that flow of hot melt played an important role in the melting process of cross section. Four types of melting mechanisms were summarized, in which viscous dissipation heat was discussed in detail, showing that viscous dissipation contributed about 10%-30% to the total energy needed during melting. Screw speed affected viscous dissipation significantly, while heating flux of barrel had little influence on it.

Abstract: The bio-oil products by continuous pyrolysis reactor, which takes place at temperatures in the range of 450-600°C, were to compare the quality of bio-oil extracted from different residual plants were, 1) Oil palm bunch [OPB], 2) Water hyacinth [WHC], and 3) Manila grass [MNG]. The preliminary analyses of three residual plants showed that the liquid yield of bio-oil obtained from OPB was highest (29.55 %) and liquid yield of bio-oil obtained from WHC was lowest (28.3 %)., at 350 rpm., and liquid yield of bio-oil obtained from OPB, WHC and MNG were 55.6, 25.55 and 25.67 %, at 150 rpm., respectively. The results showed that biomass extracted from three residual plants had good qualities because of low moisture content and high fixed carbon. The element contents of three residual plants found that high carbon content. The amount of carbon in the bio-oil obtained from OPB, WHC and MNG were 55.91, 55.57, and 55.03 wt.%., respectively., carbon was relatively high in three residual plants. Hence; In this research are concerns the feeding rate, the control gas flow, the temperatures in reactor and reactor operate for produce the hi quality of bio-oil with three residual plants of resist in Thailand.