Insulation Epoxy sheet,is insulation class B(130 degree),with good dielectric stability at high humidity,With ROSH Insulation Epoxy sheet sheet(FR4) is ... epoxy resin by procesing under pressure and heat.It is insulation class B(130 degree).With high mechanical properties at medium humidity ... electrical appliancelines,PCB test,transformers,ect.Fr4 is flame retardant. Insulation Epoxy sheet with ROSH