Patent attributes
Components and/or assemblies are applied on a substrate. The substrate has a populating side and a heat sink side, to which a heat sink is fitted. The populating side is provided with a cover, which together with a heat sink on the heat sink side of the substrate forms a type of housing for the populated substrate. Between substrate and heat sink, a guide channel for a cooling medium (e.g. air, etc.) is provided and the substrate has an opening. A fan is fitted above the opening in such a way that a cooling flow of the cooling medium generated by the fan is conducted through the guide channel on the heat sink side of the substrate and over the populating side of the substrate and thus over the mounted components and/or assemblies. The heated cooling medium is then conducted away with the aid of the cover.