Three open double panel is what it means
Because the earliest, the most difficult is the hole in the copper (how in the copper wall of copper without copper), this is the distinction between the double-sided, single-sided the most important basis.But the double double-sided, but both sides of the copper, but the hole
Which does not have copper, so that the hole without copper, but the double side of the pain of the circuit board, called false double panel, looks double panel, the actual and double-sided is different!
General circuit board double-sided, refers to the double-sided copper, and there are metal holes, that is, double-sided copper, and there are copper inside the hole, for the circuit board double-sided, the hole is particularly important copper,
