Led Printed circuit board 1.PCB experience8 years 2.PCB certificate:ISO,UL and ... 4n/cm12.3n/cm12.3n/cm warp and twist 0.02%≤0.5-0.75%≤0.5-0.75%insulation ... resister ≥5MΩ≥5MΩ≥5MΩ test voltage 50~100DCV300DCV300DCV finished board area 400×500mm500×600mm500×600mm Min line width&spacing 0 ... red black and so on Materail FR-4,Aluminium-backed board,Halogen-free,Lead-free compatible,High Tg,High CTI,CEM ...