FR4 printed circuit board (PCB)
Classic composite PCB of glassfiber and expoxy resin, available in various compounds, versions (single-/multilayer) and thickness (0.3-3.5mm)
Designation  | Material  | Note  | 
FR4 Standard  | Epoxy + glass fabrics  | Tg=130-140C, RoHS/WEEE compliant  | 
FR4 non-halogen  | Epoxy + glass fabrics  | Tg>150, CAF-resistant  | 
FR4 mid Tg  | Epoxy + glass fabrics  | Tg: 140-160C, increased thermal stability, low elongation in z-axis, high steadiness at lead-free soldering, often CAF-resistant.  | 
FR4 high Tg  | Epoxy + glass fabrics  | Tg: 160-190C, increased thermal stability, low elongation in z-axis, high steadiness at lead-free soldering, often CAF-resistant.  | 
