Wire-Sweep Study Using an Industrial Semiconductor-Chip-Encapsulation Operation

Han, Sang Hwa; Wang, K. K.; Crouthamel, D. L.

doi:10.1115/1.2792245

Cited by 22 publications

(8 citation statements)

References 5 publications

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“…Above formulation represents the most popular mid-plane model based on the Hele-Shaw flow approximation. This approach became the standard numerical framework for various commercial software packages and research codes (see, for example, references [40] to [44]) and has been extended or incorporated by other researchers to simulate the injection moulding packing phase [45,46], mould cooling [47], fibre orientation [48], residual stresses [49,50], shrinkage and warpage [51,52], as well as various special moulding processes such as coinjection moulding [53], gas-assisted injection moulding [54], microchip encapsulation [55], injection compression moulding [56], resin transfer moulding [57], etc.…”

Section: 5d Modelsmentioning

confidence: 99%

A brief history of the filling simulation of injection moulding

Cardozo

2008

Proceedings of the Institution of Mechanical Engineers, Part C:

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Injection moulding is one of the most important manufacturing processes for mass production of complex plastic parts. The quality of injection moulded parts depends not only on the material, shape, and function of the part design, but also on how the material is processed during moulding. Traditional design approaches based on intuition, prior experience, and trial-and-error methodology have been becoming less efficient and effective. With advances in numerical modelling and computer simulation techniques, there have been tremendous efforts made to develop computer simulation tools to facilitate injection moulding design and process set-up. This paper reviews the history of research and development in the filling simulation of injection moulding. The existing models are classified into three categories: one-dimensional models, 2.5D models, and three-dimensional models. The basic features and relative key techniques about these models have been discussed. The techniques of tacking the moving flow front have also been presented. It is then followed by conclusions and discussions of these mentioned models.

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Section: 5d Modelsmentioning

confidence: 99%

A brief history of the filling simulation of injection moulding

Cardozo

2008

Proceedings of the Institution of Mechanical Engineers, Part C:

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“…The above formulation represents the most popular mid-plane model based on the Hele-Shaw flow approximation. This approach became the standard numerical framework for various commercial software packages and research codes (see, for example, Refs [34][35][36][37][38]) and has been extended or incorporated by other researchers to simulate the injection molding packing phase [39,40], mold cooling [41], fiber orientation [42], residual stresses [43,44], shrinkage and warpage [45,46], as well as various special molding processes such as co-injection molding [47], gas-assisted injection molding [48], microchip encapsulation [49], injection compression molding [50], resin transfer molding [51], etc. The mid-plane models dominated the numerical simulation of injection molding for about 20 years.…”

Section: Mid-plane Modelsmentioning

confidence: 99%

Three Models of the 3D Filling Simulation for Injection Molding: A Brief Review

Cardozo

2008

Journal of Reinforced Plastics and Composites

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This article reviews the state-of-the-art research and development in the 3D filling simulation of injection molding, most notably the different models. The article organizes prior studies into three sequential categories, namely, mid-plane models, surface models, and solid models. In the mid-plane models, the arbitrary planar mid-plane is used to represent the three-dimensional geometry of the part. Their model and formulation are presented based on the Hele—Shaw approximation. The article further discusses the main disadvantage of the mid-plane models, which introduces the surface models. The surface models represent a three-dimensional part with a boundary or skin mesh on the outside surfaces of a solid geometric model. This kind of model still adopts the Hele—Shaw approximation, but can avoid the re-modeling of the mid-plane. Subsequently, the situations that cannot be accurately predicted using the Hele—Shaw approximation are discussed, in which a full 3D simulation has become a promising solution. The leading 3D simulation approaches are summarized, including the finite element method, the finite volume method, the control-volume-based finite-element-method, and the boundary element method. The tracking algorithms of the melt fronts are also described.

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“…There have been studies of mold filling analysis in microchip encapsulation, however, focuses were given to the single die, not to 3D packaging such as staked-die packages [1][2][3][4]. Therefore, in this study, a three dimensional computational fluid dynamics (CFD) analysis has been performed on a stacked-die package, using a commercially available injection-molding software package, Moldflow, to establish the understanding of the mold flow characteristics in the complicated geometry during the encapsulation process on the effect of different design parameters.…”

Section: Introductionmentioning

confidence: 99%

Three Dimensional Flow Analysis During Injection Molding Process For Stacked-Die Packages

Moon

Cheng

et al. 2007

2007 32nd IEEE/CPMT International Electronic Manufacturing Technology Symposium

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The three-dimensional numerical simulation has been performed to study mold flow characteristics during injection molding process of stacked die packages. The modeling results revealed that flow front shape is highly non-uniform around the die stack-up units and is dependent on various design parameters including mold cap clearance, mold compound material properties, as well as the die stack-up geometric configurations. It was demonstrated that validated flow model can help guiding the design, material, and process optimization of 3D packaging development. IntroductionAs the demand for speed and functionality increases for electronic handheld devices such as cell phones and PDAs, a stacked die package becomes one of the preferred options to provide the high performance and multi-functionality for a given electronic component. While the injection molding process is widely used for the microchip encapsulation, the various design, materials and process parameters will need to be further optimized for defect free process due to the increased level of complexity in package architecture.There have been studies of mold filling analysis in microchip encapsulation, however, focuses were given to the single die, not to 3D packaging such as staked-die packages [1][2][3][4]. Therefore, in this study, a three dimensional computational fluid dynamics (CFD) analysis has been performed on a stacked-die package, using a commercially available injection-molding software package, Moldflow, to establish the understanding of the mold flow characteristics in the complicated geometry during the encapsulation process on the effect of different design parameters. Numerical Model DescriptionThe mass, momentum, and energy conservations for mold flow in the filling phase can be mathematically described by equations (1) through (3), respectively [2,5].-P+V(pv)0=0 (1) at (, +V(pvv)=-Vp+Vr+pg (2) OT (,cupat VT ,8'at i+y'+kVT+H at where iv is the velocity vector, p the density, 77 the viscosity, p the static pressure, r the stress tensor, and y the shear rate. Also the first term in the right hand side in equation (3) is the energy generation rate due to compression/expansion of the polymer melt followed by the energy generation rate due to viscous dissipation. The last term in equation (3) is the exothermic heat generation rate due to curing, where a is the degree of cure and H is the total heat of the cross linking reaction.In this simulation, the curing reaction is described with Kamal's autocatalytic model as shown in equation (4). (4) 3r= (K1 +K2ajXI-a)' K is the Arrhenius equation constant; m and n are the reaction orders. The temperature Arrhenius equation constant K is commonly described by equation (5).Ki Ai exp RT (5) Ai is the pre-exponential factor; Ei is the activation energy; R is the universal gas constant.For the non-Newtonian viscosity behavior of the polymer melt, the Cross-Exponential Macosko model [6] is used as described by following equation.

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Wire-Sweep Study Using an Industrial Semiconductor-Chip-Encapsulation Operation

Cited by 22 publications

References 5 publications

A brief history of the filling simulation of injection moulding

A brief history of the filling simulation of injection moulding

Three Models of the 3D Filling Simulation for Injection Molding: A Brief Review

Three Dimensional Flow Analysis During Injection Molding Process For Stacked-Die Packages

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