Influence of build-up construction and resin-content on mechanical behavior of printed circuit boards

The aerospace and high performance (AHP) electronics industry leans henceforth on the technologies developed for consumer applications. However, the requirements of AHP products in terms of reliability are stronger than for consumer ones. One of the factors to improve the reliability in thermal cycling of electronic assemblies is the selection of base materials for Printed Circuit Boards (PCB). In addition, with the increase of circuit density in electronics and in particular the incoming of new technologies (such as stacked muvias, embedded active components), the PCB becomes a critical element for the reliability of the assembly, and its stack-up construction more and more complex. A previous work clearly highlights that the choice of the base material has an important consequence on the reliability of the electronic assemblies. Specially for ceramic and large plastic BGA components. This work carries on the characterization of PCB mechanical properties as a function of its base materials and board stack-up construction. The main conclusions of this study show that the physical data supplied by the manufacturers of base materials are not sufficient or not exact, and these properties are very dependent on the total resin and glass- fibers contents. In addition, finite element models must take into account the multilayer architecture and material properties as a function of temperature.