Below factors should be considered when we choose the material for PCB:
(1)The material’s Tg value should be greater than the operation temperature;
(2) Low CTE material has good performance of thermal stability;
(3)Good thermal resistance performance: Normally PCBs are required to resist 250℃ for at least 50s.
(4) Good flatness;
(5) In consideration of the electrical properties, low loss/high permittivity material is used on high frequency PCB; Polyimide glass fiber substrate used for flexible PCB; Metal core is used when the product has strict requirement of heat dissipation.