Method of manufacturing a capacitive electrical device

A method of manufacturing a capacitive electrical device, wherein the method comprises:

• a) bonding a first electrical insulation film with a second electrical insulation film to obtain a single electrical insulation film that has a larger surface area than any of the first electrical insulation film and the second electrical insulation film has alone,
• b) providing a conductive layer onto the single electrical insulation film, and
• c) winding the single electrical insulation film and the conductive layer around a shaft concurrently to obtain a layer of the single electrical insulation film and a layer of the conductive layer wound onto the shaft for forming the capacitive electrical device,
• the first electrical insulation film and the second electrical insulation film being bonded to form the single electrical insulation film prior to them being wound around the shaft.