refer to the user guide, PCB material: the material used on EVK is 185HR.
for other material select, pls refer to this
Material characteristics such as the Coefficient of Thermal Expansion (CTE) should be considered. The CTE describes how a material changes dimension with temperature. Ideally, a PCB material’s CTE should be closely matched to copper, which is about 17 ppm°C. CTE is a concern because as the PCB expands during heating, it can elongate plated via holes and cause fracturing.
If the CTE is closely matched to copper, expansion of the PCB material and copper will be more uniform and the plated via holes will be more robust during thermal cycling.
