Surface plasmon-polaritons in deformed graphene excited by attenuated total internal reflection

In the present work we theoretically investigated the excitation of surface plasmon-polaritons (SPPs) in deformed graphene by attenuated total reflection method. We considered the Otto geometry for SPPs excitation in graphene. Efficiency of SPPs excitation strongly depends on the SPPs propagation direction. The frequency and the incident angle of the most effective excitation of SPPs strongly depend on the polarization of the incident light. Our results may open up the new possibilities for strain-induced molding flow of light at nanoscales.

Evaluation by nanoindentation of technological products manufactured by pulse injection molding process

During conventional polymer injection molding, flow- and weld lines can arise at the molded parts caused by disturbed polymer melt flow when it crosses different parts of the equipment. Such processed plastic goods have discrete zones of inhomogeneities of very small dimensions. In order to stabilize the melt flow and to equalize dimensions of such defective products, an approach for pulse injection molding is applied during production of polymer packagings. Testing methods used for evaluation of macromechanical performance of processed polymer products are not readily applicable to estimate the changes in visual surface obtained during pulse injecting. To overcome this testing inconvenience the performance of processed packagings is evaluated by nanoindentation. Using this method, a quantitative assessment of the polymer properties is obtained from different parts of technological products.

The Optimization of Gate Design of Side-Axis Part in Air Switch

Gate location and number setting are the key technology in injection molding. Flow direction and balanced flow of polymer depend on gate location and number whose optimization can promote product quality. Gate location and number of air switch side-axis were analyzed in injection flowing process with CAE software Moldflow. According the simulation results, the best gate location and number were set up. The study result is preparations for further injection system design and it provides evidence for mold optimization design. By utilizing the simulation results, the product quality is improved and the designing cycle is shortened.

Molding Flow Modeling and Experimental Study on Void Control for Flip Chip Package Panel Molding with Molded Underfill Technology

Increasing challenges are faced to ensure moldability with rapid advances in flip chip technology such as decreasing bump pitch and stand-off height, especially when commercial Moldable Underfill (MUF) is used and in particular, during panel level molding. One key challenge faced is severe void entrapment under the die. Experiments involving a large DOE matrix, which require significant time and process resources, are typically used to solve this issue. 3D flow simulation can be used to optimize the process to reduce defects without doing actual runs. Mold flow simulation can effectively reduce the design-to-implementation cycle time, identifying key problems before actual fabrication. In this paper, 3D mold flow simulation using Moldex3DTM V10 is applied to transfer molding to optimize design and process parameters. This paper proposes and verifies a systematic method that can save computational resources by using 2 steps analysis: simplified panel simulation and single package simulation. The initial step, simplified panel level simulation, is to optimize the process parameters to obtain balanced melt front. The second step is to study on the package level the effect of various package-scale parameters. This analysis provides a prediction of the void location and an insight on the appropriate parameters to minimize void problem. The actual voids location and size from the experiment was captured by SAT machine and short shots were obtained. For final validation, a complete panel-level flow model is built, where the process and design parameters adopted in the actual molding were implemented. The mold filling simulation showed good correlation with the experimental short shots and actual void location. With optimized parameters from the simulation used as guidelines, experimental tests were conducted and the study showed that the simulation is a useful tool to optimize the molding process.

Injection Molding Flow Simulation of Thin-Walled Slender Tube and Optimization of Combined Cavity

Thin-walled slender tubes are produced by injection molding, where there might be defects such as short shot, excessive warpage and uneven temperature distribution. In this paper, injection process analysis was carried out. The 3D modeling technology of Pro/E established a solid model of thin-walled slender tube. MPI (Moldflow Plastics Insight) was used for executing injection molding flow simulation. Gate location and gate number was optimized. Filling system and cooling system of the combined cavity was optimized by analysis of flow, cool and warp. The results can be used for supplying reliable data of mold designing and manufacturing, reducing the engineering mold trial time, decrease the manufacturing cost. The configuration and dimensions of the injection gate can be determined by the computer program before the molds are actually manufactured. The potential defects were forecasted. Therefore, the designers can quickly optimize the mold design.

Simulation of Molding Flow of Sheet Molding Compound in Complicated Dies

Based on generalized Hele-Shaw(GHS) model, numerical simulation of compression-molding flow of sheet molding compound (SMC) in complicated dies is realized by control volume/finite element method (CV/FEM). Finite element computing and post analysis programs have been written. The flow fronts of SMC charge during compression molding are tracked, and the time needed of mold filling in complicated dies is predicted. The results of simulation are helpful for the placement of SMC charge, the design of mold and the optimization of technological parameters.