Effect of processing parameters on bulge-forming Polycarbonate parts

According to the data of the experiment made in mechanical tensile of Polycarbonate in high temperature, experiments were done to polycarbonate sheet by hot gas pressure bulge-forming. It was found that selecting and combination of the processing parameters were vital to the quality. In the experiments and numerical simulation with the software of DYNAFORM, the processing parameters have been studied.The results showed that the method of discontinuous pressure and pressure preservation advantage the forming; when temperature and pressure meet the forming conditions, the longer time of pressure preservation promotes sufficient forming.

A Double High-Voltage p-LDMOS and Its Compatible Process for PDP Scan-Driver ICs

A high-voltage p-LDMOS（HV-pMOS） with field-oxide as gate dielectric and a RESURF drain drift region to undertake high gate-source voltage and drain-source voltage for the scan driver chip of plasma display panels （PDP） is purposed based on the epitaxial bipolar-CMOS-DMOS （BCD） process. The key considerations and parameters of the design are discussed：the thickness of gate dielectrics is 1mm and the area of the device is 80μm × 80μm. Only 18 photoetching steps are needed in the developed process,which is compatible with standard CMOS, bipolar, and VDMOS devices. The breakdown voltage of the HV-pMOS in the process control module （PCM） is more than 200V. The results are favorable for 170V PDP scan driver chips,which contribute to the competitive cost efficiency.

Simulation and formability analysis of drawing process for automotive B-pillar

The numerical simulation on drawing process of automotive B-pillar was carried out on AutoForm software,and dangerous forming areas were discovered.The processing parameters,such as the layout of drawbeads,blank holding force and the shape of blank,were adjusted and optimized according to the simulation results.Results indicate that the quality defects can be forecast and removed,which improves the stability of forming process.The cost of design is decreased and the research cycle is shortened.It is proved that the drawing process and die design of B-pillar forming are feasible in actual production.

Key Issues in Developing Numerical Models for Artificial Weather Modification

The scientific foundation of artificial weather modification is rneso- and small-scale dynamics and cloud-precipitation microphysics. Artificial weather modification requires the realistic coupling of weather patterns, dynamical pro- cesses, and microphysical processes. Now that numerical models with weather dynamical characteristics have been widely applied to artificial weather modification, several key points that should not be neglected when developing numerical models for artificial weather modification are proposed in this paper, including the dynamical equations, model resolution, cloud-precipitation microphysical processes, numerical computation method, and initial and boundary conditions. Based on several examples, approaches are offered to deal with the problems that exist in these areas.