Assessment of thermo mechanical properties of crosslinked epoxy mesoscale approach — Preliminary results

Usage of polymers materials in microelectronics and especially in packing is nowadays common. Polymer materials are used for example in case of encapsulation, underfills for flip chip, moulding compound, electrically or thermally conductive adhesive, flexible electronics, materials for Printed Circuits Board (PCB), etc. Reliability in electronic packaging depends highly on thermomechanical material properties. Those properties are often used in numerical prototyping in order to predict the vital reliability parameters. Most often such properties are difficult, costly and time consuming in experimental assessment e.g. viscoelasticity. Additionally in case of thin layers such properties will depend on the layer thickness and substrate material. Thus nowadays there is a noticeable interest in assessing certain thermomechanical material properties by using molecular modelling techniques. Advanced computing methods gives opportunity of reducing the cost and shorten time. Molecular modeling (MM) gives very accurate information but the calculation are time consuming. And the gap between MM and Finite Element Method (FEM) is big. Usage of mesoscale could fill the gap. Authors examined common in electronic packaging epoxy resin using mesoscale approach. The change of volume in the function of temperature and Young modulus were assessed. From this data Coefficient of Thermal Expansion (CTE) and glass transition (Tg) were evaluated. The results are preliminary, influence of all simulation parameters are not fully known.