A connecting device for the electrically conductive connection of electronic components and a substrate. The connecting device is formed as a film composite formed of at least one insulating film and at least two electrically conductive films disposed on opposite sides of the insulating film. The film composite is formed as a layer construction of a conductive film alternating with an insulating film, wherein at least one conductive film is structured and thus forms conductor tracks. Furthermore, at least one conductive film of a main area of the film composite is made of a first metal and has at least one film section having a layer of a second metal that is thinner in comparison with the thickness of the first layer.