The invention to a method of making an interconnector assembly for electrically interconnecting solar cells, wherein the method comprises: feeding a plurality of (preferably elongated) electrical conductors that form an conductor array defining interspaces that are free from conductors; and applying at least one sheet, preferably made of electrically insulating material, to a side of the conductor array, wherein the sheet has at least one contact zone coming into contact with the conductors and intermediate portions overlapping with the interspaces of the conductor array. The invention also refers to an apparatus for fabricating an interconnector assembly for electrically interconnecting solar cells and to a rotatable heating drum.