Method and apparatus for producing RFID transponders (400) arranged on a carrying substrate, comprising:providing a first substrate (100), the first substrate having at least one antenna element (101) arranged thereon, and preferably several antenna elements arranged sequentially thereon along a longitudinal extension of the first substrate, each antenna element being formed by an electrically conductive pattern; providing a second substrate (200), the second substrate (200) having at least one RFID strap, each RFID strap comprising an IC (202) and at least one contact pad (201) coupled to the IC, and preferably several RFID straps being arranged sequentially along a longitudinal extension of the second substrate; and electrically connecting an antenna element (101) on the first substrate to the at least one contact pad on the second substrate by bringing said first and second substrates together, thereby bringing said antenna element in mechanical contact with said at least one contact pad, and heating the contact pad(s) to a temperature at least equal to a characteristic melting point of said at least contact pads, thereby electrically connecting the antenna element to said at least one contact pad.