What are the types of boards on board?
94V0: Flame-retardant cardboard (die punch) 22F: Single-sided half-glass plate (die-punching) Fr-1 CEM-1 (mold punching) CEM-3: double-sided half-glass plate (in addition to double-sided cardboard outside the double-sided low-end material, a simple double-sided board can use this material (single-sided glass fiberboard (must be computer drilling, can not die) , Than the FR-4 will be cheaper 5 to 10 yuan / square meter) ...
