... : 30mil Min. drilling slot size: 0.6mm Solder mask color: green, black, blue, white, yellow, and matt, ... etc. Solder mask hardness: 6H Legend/Silkscreen Color: white, yellow, black, etc. Surface Treatment: HAL, ... blind/buried vias, characteristic impedance control, Rigid-flex board etc. Reliability Test: flying probe test/fixture test, ... and twist: ≤0.7% Flammability: 94V-0 LED Circuit Board