FR4,FR1,CEM-1,CEM3 copper clad laminated sheet can supply, made for PCB products, under RoHS, UL, SGS etc. ... FR2, CEM3, FR4 .Thickness:0.6mm,0.8mm,1.0mm,1.2mm,1.6mm,2.0mm .Thickness of copper:18um, 35um ... or dirty can be easily. removed by density 1.02g/cm3 hydrochloric acid or proper organic solution . ... use are not allowed .4) Usually used in PCB of computers, home electric appliances and other lines . ...