Flexible circuit board with thermally conductive connection to a heat sink

A flexible circuit board comprising:

• an cover layer having an upper side, a lower side, and openings, the cover layer being electrically insulating;
• an electrical component with electrical contacts arranged on the upper side of the cover layer;
• a conductive track structure with contact regions arranged on the lower side of the cover layer, wherein the electrical contacts of the electrical component are each electrically conductively connected to one of the contact regions through respective ones of the openings;
• a heat sink thermally conductively connected through the cover layer to the electrical component;
• and
• an electrically insulating layer arranged between the heat sink and the lower side of the cover layer on which the conductive track structure is arranged, wherein the electrically insulating layer electrically insulates the conductive track structure from the heat sink,
• wherein the electrically insulating layer includes at least one first region consisting of a material with a thermal conductivity of at least 1 W/(mK) and at least one second region comprising a material with an adhesive effect configured to fasten the cover layer on which the conductive track structure is arranged to the heat sink, the at least one first region being arranged in areas at least under the contact regions of the conductive track structure and the at least one second region is arranged in areas other than the at least one first region,
• wherein the at least one first region of the electrically insulating layer underneath at least the contact regions of the conductive track structure is a thermally conductive foil that lies directly against the contact regions on the one side and against the surface of the heat sink on the other side,
• wherein the material of the at least one first region does not have the adhesive effect, and
• wherein the at least one second region of the electrically insulating layer is a foil having an adhesive layer on both sides.