Influence of Cure Dependency of molding Compound Properties on Warpage and Stress Distribution During and After the Encapsulation of Electronics Components

Conference paper (2009)

Authors

TC Falat Computational Design and Mechanics - Mechanical, Maritime and Materials Engineering
K.M.B. Jansen Computational Design and Mechanics - Mechanical, Maritime and Materials Engineering
J de Vreugd Computational Design and Mechanics - Mechanical, Maritime and Materials Engineering
S Rzepka External organisation
Research Group
Computational Design and Mechanics (Mechanical, Maritime and Materials Engineering) (TU Delft)
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Published Date

2009

Language

Undefined/Unknown

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Faculty

Mechanical, Maritime and Materials Engineering

Department

Precision and Microsystems Engineering

Research Group

Computational Design and Mechanics

Abstract

Commercial FEM software codes do not directly support the cure dependency of polymers behavior. In electronics packaging, for example, cure shrinkage of the molding compound is consequently treated as a surplus to thermal contraction and its changes in visco-elastic behavior during curing are usually ignored. This gives rise to inaccurate results and may cause difficulties even in recognizing factors important for further optimization. This work introduces a cure dependent visco-elastic material model being implemented into ANSYS by USERMAT, the user material subroutine. The results obtained when simulating the warpage of bi-material strips during and after curing with the full scale material model were compared to those obtained with simplified material models. Varying the geometric configuration different changes in the deformation results have been found caused by cure dependency anywhere between -10%, 0%, and +20%. Hence, correct results can only be achieved in general case with models accounting for cure dependency directly.