IEC61249-2-47:2018(E) gives requirements for properties of non-halogenated epoxide non?woven reinforced core/woven E-glass reinforced surface laminate sheets of thermal conductivity and defined flammability (vertical burning test), copper-clad for lead-free assembly in thicknesses of 0,60mm up to 1,70mm. The flammability rating is achieved through the use of non-halogenated fire retardants reacted as part of the epoxide polymeric structure. The glass transition temperature is defined to be 105°C minimum. Thermal conductivity is defined to be (2,0 ± 0,30)W/(m•K).