Computational Modeling and Validation of the Encapsulation of Plastic Packages by Transfer Molding

Abstract

This paper presents, discusses, and compares results from experimental and computational studies of the plastic encapsulation process for a 144-lead TQFP package. The experimental results were obtained using an instrumented molding press, while the computational predictions were obtained using a newly-developed software for modeling transfer molding processes. Validation of the software is emphasized, and this was done mainly by comparing the computational results with the corresponding experimental measurements for pressure, temperature, and flow front advancement in the cavities and runners. The experimental and computational results were found to be in good agreement, especially for the flow-front shapes and locations. [S1043-7398(00)00502-8]

Plastic Ball Grid Array Encapsulation Process Simulation on Rheology Effect

“…In the simulation model, the EMC and air are assumed incompressible and the governing equations that described the fluid flow are conservation of mass, conservation of momentum and conservation of energy [7]- [8]. FLUENT normally solves the governing equations using Cartesian spatial coordinates and velocity components as listed below.…”

“…Several models have been used to predict the relationship between viscosity (µ) and the degree of polymerization. The Castro-Macosko model has been applied by Nguyen et al [8] and Alpem et al [9] is selected to use in this simulation. It is described as follows:…”

Influence of Material Properties on the Fluid-Structure Interaction aspects during Molded Underfill Process

“…Kamal's equation [6,9] described the curing effect and integrated with the Castro-Macosko model in the current study. The rate of the chemical conversion of the compound in this model can be predicted as follows: ,…”

“…In the simulation, the encapsulant material was assumed as generalized Newtonian fluid (GNF). The Castro-Macosko model [6,9] was applied to predict the relationship between the viscosity and degree of polymerization and describe the viscosity of the encapsulant material as follows:…”

“…In the current study, the EMC flow front profile, chip and solder bump stress were investigated through the FSI simulation. Three types of EMC [6][7][8] (e.g., Sumikon EME 6300HN, SUMITOMO 6300 HG) with different material properties, namely Case 1, 2 and 3 were considered in the analysis.…”