This part of IEC 62258 has been developed to facilitate the production, supply and use of semiconductor die products, including: • wafers; • singulated bare die; • die and wafers with attached connection structures; • minimally or partially encapsulated die and wafers. This part of IEC 62258 determines the information required to facilitate the use of thermal data and models for simulation of the thermal behaviour and verification of the correct functionality of electronic systems that include bare semiconductor die, with or without connection structures, and/or minimally packaged semiconductor die. It is intended to assist all those involved in the supply chain for die devices to comply with the requirements of IEC 62258-1 and IEC 62258-2.