In this study the bending reliability of an isotropic conductive adhesive (ICA) filled between two printed circuit foils (PCF) as interconnection for a System-in-Foil is evaluated. The filling is realized by a Jet-Dispense process on oxygen plasma treated, as well as non-plasma treated foils. The samples are tested on a bending test setup capable of real-time electrical measurements during bending. A significant improvement of the bending stability is achieved with the plasma treatment process, while the main failure mechanism for the non-plasma treated samples is delamination at the pad-adhesive interface.