[en] For several years, Thales Alenia Space Etca industry, located in Charleroi, designs and develops modular equipments intended to be embarked on board of spatial vehicles. During their operating life, these equipments are subjected to severe mechanical vibrations which can produce failures of the electronic and magnetic components, as for examples the contact losses of electromagnetic relays or the appearance of cracks in the ferrite cores. Thales and the Faculte Polytechnique de Mons (FPMs) develop numerical tools in order to simulate their dynamic behavior to vibrations. This paper presents a Finite Elementmodel of electronic units composed by a multilayer PCB and an aluminium frame used for stiffening and fixing the PCB inside the electronic box. The PCBs are multilayer structures, each layer being composed by a non-conductive polyimide substrat coated by copper sheets. The conductive pathways are etched on the PCB by removing the unwanted copper by photographic techniques. The electronic and magnetic components are fastened to the PCB with thermal glue.
