... 6-LayerSurface finished:immersion gold;Line width&space6/8milsFinished copper:3ozSolder mask:green;Material:FR4.Certificates:CQC,ISO.TS16949,SGS,ISO9001, ... dissipation more better.The thicker the copper can carry more greater current.why choose heavy copper pcb board ?1-Elimination of complex ... build a long term relationship with them,that's why kdpcb is difference from others pcb suppliers in china. ...