The present application relates to a method of manufacturing a heat sink from a plurality of extruded lamellas, each lamella including a base portion having a top surface, a bottom surface, and two side surfaces, each lamella further including a fin portion extending from the top surface of the base portion, wherein the base portion is wider than the fin portion. The method includes aligning the base portions of the plurality of lamellas with the fin portion of each lamella extending in the same direction and the side surfaces of adjacent base portions facing each other; pressing the base portions of adjacent lamellas into contact with each other by applying a force to the side surface of at least one of the base portions; and welding the bottom surfaces of adjacent base portions together. A heat sink and a lamella for use in manufacturing a heat sink are also disclosed.