TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Process: The internal structures are formed in and/or on the metal film or foil by (b) structurization and (b') selective etching of the exposed areas.Preferred methods of structurization (b) are :(1) coating the metal with a photosensitive layer, selective exposure and exposure of the metal in all parts corresponding to the structures;(2) coating the metal with a screen printing lacquer in areas not corresponding to the structures; or(3) laminating a perforated film on the metal, which has perforations at all points corresponding to the structures.The photosensitive layer, lacquer or perforated film is removed between stage (c) and (B) or after stage (B). Before stage (B) other metal or adhesive layers may be applied to the areas of the first metal film or foil without the functional layer by covering only the functional layer with protective film, forming other metal or adhesive layers on the areas exposed by removing the photosensitive layer, lacquer or perforated film and removing the protective film. The internal structures in the first metal film or foil are produced by forming a functional layer on a first metal film or foil; forming the internal structures by method (1), (2) or (3); (b') forming cavities in the functional layer by selective etching of the exposed areas; and forming metal only in these cavities. A planar surface formed by the metal pins and photosensitive layer, lacquer or perforated film is produced by grinding and/or polishing. The photosensitive layer, lacquer or perforated film is removed before stage (B). The individual layer(s) and sealing segment are bonded by soldering or with adhesive.    TECHNOLOGY FOCUS - METALLURGY - Preferred Materials: The first metal film or foil consists of copper, steel or aluminum; and the functional layer consists of a sub-group VIII metal or alloy, preferably platinum, iridium, palladium or gold. SPECIFIC MATERIALS - Specific examples of the metal for the first film or foil are copper and aluminum. Specific examples of the metal for the functional layer are platinum, iridium, palladium and gold.