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Hsu C.-C.,National Tsing Hua University | Wang T.-C.,CoreTech System Moldex3D Co. | Chen Y.-C.,CoreTech System Moldex3D Co. | Lin Y.-K.,CoreTech System Moldex3D Co.
Proceedings - Electronic Components and Technology Conference | Year: 2014

This paper reports a perspective investigation of computational modeling of fluid-structure interaction (FSI) in molded integrated-circuit(IC) packaging. The investigation is carried out through two aspects, respectively on interaction between the fluid and structure in the encapsulation process and appropriate methodology for modeling. We present a novel and integrated method to predict the FSI during the encapsulation process. This method not only provides more accurate melt front and pressure result but also predict precisely the FSI behavior through the dynamic mesh deformation technique simultaneously in accordance with continually deformed geometry (two way FSI). This is different from previous study that only one way considered fixed geometry (one way FSI) during encapsulation. Moreover, the experimental data for single- and stacked-chip were compared with the simulation results for two way FSI implementation to verify flow front advancement. From a real paddle shift case study, the result indicates that the deflection prediction is well predicted and could predict void formation well when it considers two way FSI effect. It is expected that this paper could clarify relevant issues in prediction of FSI in IC packaging and induce more considerations for modeling FSI using two way FSI multiphase flow method. © 2014 IEEE.

Hsu F.-H.,CoreTech System Moldex3D Co. | Wu B.-H.,CoreTech System Moldex3D Co. | Huang C.-T.,CoreTech System Moldex3D Co. | Chang R.-Y.,National Tsing Hua University
AIP Conference Proceedings | Year: 2014

Cooling stage is critical in injection molding process. A well designed cooling system can effectively shorten cycle time and improve product quality. Three-dimensional cooling analysis has been embedded in injection molding simulation which provides a useful tool for cooling system design validation. However, the current simulation tool is not perfect yet since it does not consider turbulent flow and pipe surface roughness effect. In the current study, a latest simulation tool was applied which can predict the turbulent flow effect on cooling. Two cooling systems (conventional and conformal) were simulated and compared to each other. Turbulence model and surface roughness effects were also studied. The simulation results show a good agreement with experimental data which is helpful at the design stage of an injection molding cooling system. © 2014 American Institute of Physics.

Shiu T.-Y.,CoreTech System Moldex3D Co. | Huang C.-T.,CoreTech System Moldex3D Co. | Chang R.-Y.,National Tsing Hua University | Hwang S.-S.,Chien Hsin University of Science and Technology
AIP Conference Proceedings | Year: 2014

Microcellular injection molding process is a promising solution for products with special requirements such as weight reduction, extra thin wall, high dimensional stability, clamping force reduction, etc. Despite microcellular foaming application used in reciprocating screw injection molding machine was built more than a decade, some limitations, such as poor surface quality or poor foaming control, confine the usage of this technology. Earlier CAE simulation tool for microcellular injection molding was not successful due to insufficient physical and computational considerations, limited by complicated bubble growth mechanism; so that, an economic and efficient tool for examining foaming quality of injection foaming product was lack. In this study, a recent developed three-dimensional simulation tool is used to predict injection foaming process. Predictions are carried out with commodity polypropylene and polystyrene with nitrogen and carbon dioxide supercritical fluids (SCFs). Comparisons of simulations between microcellular injection molding with and without counter pressure are discussed to provide insights into the correlation of surface quality and cell size distribution near the surface of product. Furthermore, comparisons between simulation predictions and experimental results of molding process, which is featured with dynamic mold temperature and gas counter pressure, are given for understanding quality improvement by controlling foaming morphology, and benefit of industrial application. © 2014 American Institute of Physics.

Huang C.-T.,Tamkang University | Lin C.-P.,CoreTech System Moldex3D Co. | Sun S.-P.,CoreTech System Moldex3D Co. | Tseng S.-C.,National Yunlin University of Science and Technology | Chang R.-Y.,CoreTech System Moldex3D Co.
International Journal of Materials and Product Technology | Year: 2016

Multiple component moulding (MCM) is one of the great methods to fabricate the modern injection products. Due to many procedure combinations, it is very difficult to know the detailed process. Besides, because of its complicated nature and the unclear physical mechanism, using trial-and-error method cannot realise and manage the mechanism effectively. In this study, we will review various MCM technologies, including over-moulding, and co-injection moulding, and study these two applications in more details. Results show that the product geometries, process condition, and moulded materials will affect the product quality. The physical mechanism of warpage in a sequential over-moulded part is due to the unbalance between the volumetric shrinkage during filling/packing and the thermal unbalance from cooling. The warpage behaviour for co-injection moulding is more complicated because of the uncertain interface. However, one of the keys to manage the warpage is the control of the core penetration. Copyright © 2016 Inderscience Enterprises Ltd.

Hsu C.-C.,National Tsing Hua University | Chiu H.-S.,CoreTech System Moldex3D Co. | Chang R.-Y.,National Tsing Hua University
Annual Technical Conference - ANTEC, Conference Proceedings | Year: 2013

The objective of this study is to develop a simulation tool of compression molding (CM) process to get a comprehensive understanding of the whole process. We primarily focused on numerical simulation of the flow during mold closure in compression molding process. The complex advancing flow front is simulated by means of novel moving mesh boundary technique to realize the effect of process conditions. The behavior of squish flow could be seen from the analysis. Furthermore, we also investigated the fiber orientation states in CM short-fiber-reinforced parts with rib geometry. By means of simulation tool, the distribution of fiber orientation can be tailored through the interpolation of fiber orientation tensor.

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