TY - THES

T1 - Characterization and modeling of the cure-induced shrinkage of an epoxy resin used in organic laminate based electronic modules

AU - Zündel, Julia Verena

N1 - embargoed until 19-06-2023

PY - 2018

Y1 - 2018

N2 - Regarding printed circuit board industry, miniaturization and the technique of embedding electrical components in the internal organic laminate based layers lead to an ever increasing complexity of the designs as well as the manufacturing processes of the boards. As a consequence, reliable finite element simulations have become more important because they can support the investigation of both the producibility and the reliability of the requested electronic modules prior to manufacturing. Detailed knowledge about the time- and temperature-dependent material behavior of all components is essential for this purpose. However, deformation and internal stresses due to resin shrinkage are mostly neglected in finite element simulations of electronic modules until now. The primary focus of the present master thesis was therefore to determine the cure-induced shrinkage of an epoxy resin of an organic laminate commonly used in printed circuit board manufacturing. For this purpose, various measurement methods were investigated and evaluated with regard to reproducibility and comparability. The influences of the temperature and the pressure applied during specimen preparation on the material behavior of the resin and consequently on the measured shrinkage values were investigated as well. The second part of the thesis focused on the implementation of the determined shrinkage into the material model of the resin in the finite element software Abaqus FEA. A simple implementation approach was chosen, combining the effects of thermal expansion and cure-induced shrinkage into one temperature-dependent material characteristic. It could be shown that thermomechanical analysis is the most suitable method among the examined measurement techniques. Isothermal measurements at the curing temperature of the resin were performed and the dimensional changes of the specimens were recorded. By evaluating the measured data a shrinkage value of approximately 1% was obtained for the investigated resin. Temperature modulated thermomechanical analysis has the potential to be used for online shrinkage measurement; further research of this complex technique is needed though. The combination of the other investigated measurement methods, namely density measurements and rheometry, and the chosen specimen preparation method turned out to be not suitable for the determination of the resin shrinkage.

AB - Regarding printed circuit board industry, miniaturization and the technique of embedding electrical components in the internal organic laminate based layers lead to an ever increasing complexity of the designs as well as the manufacturing processes of the boards. As a consequence, reliable finite element simulations have become more important because they can support the investigation of both the producibility and the reliability of the requested electronic modules prior to manufacturing. Detailed knowledge about the time- and temperature-dependent material behavior of all components is essential for this purpose. However, deformation and internal stresses due to resin shrinkage are mostly neglected in finite element simulations of electronic modules until now. The primary focus of the present master thesis was therefore to determine the cure-induced shrinkage of an epoxy resin of an organic laminate commonly used in printed circuit board manufacturing. For this purpose, various measurement methods were investigated and evaluated with regard to reproducibility and comparability. The influences of the temperature and the pressure applied during specimen preparation on the material behavior of the resin and consequently on the measured shrinkage values were investigated as well. The second part of the thesis focused on the implementation of the determined shrinkage into the material model of the resin in the finite element software Abaqus FEA. A simple implementation approach was chosen, combining the effects of thermal expansion and cure-induced shrinkage into one temperature-dependent material characteristic. It could be shown that thermomechanical analysis is the most suitable method among the examined measurement techniques. Isothermal measurements at the curing temperature of the resin were performed and the dimensional changes of the specimens were recorded. By evaluating the measured data a shrinkage value of approximately 1% was obtained for the investigated resin. Temperature modulated thermomechanical analysis has the potential to be used for online shrinkage measurement; further research of this complex technique is needed though. The combination of the other investigated measurement methods, namely density measurements and rheometry, and the chosen specimen preparation method turned out to be not suitable for the determination of the resin shrinkage.

KW - Epoxidharz

KW - Härtungsschrumpfen

KW - thermomechanische Analyse

KW - Leiterplatten

KW - cure shrinkage

KW - epoxy resin

KW - thermomechanical analysis

KW - printed circuit boards

U2 - 10.34901/mul.pub.2023.113

DO - 10.34901/mul.pub.2023.113

M3 - Master's Thesis

ER -