The present invention relates to an RFID tag comprising a heat-resistant substrate made of a plastic film and capable of withstanding temperatures up to 200° C., an antenna formed on the surface of the substrate, an integrated circuit on a silicon chip electrically connected to the antenna and a joint for attaching the chip to the substrate on that the chip is capable of connecting electrically to the antenna. The joint is made of an anisotropically conductive adhesive capable of withstanding temperatures up to 200° C. and having a thermal expansion coefficient essentially similar to that of the silicon chip.