Six-layer or four-layer PCB board What does this mean? Is the line inside the circuit board
Yes, the line can be inside the circuit board. You take the circuit board, look at the light to see it.
But you have to ask the question he answered is correct, the line in the internal, through the hole (HDI board with blind holes and buried holes) to connect the layers of the li
In fact, only four layers in the outer line after the anti-welding because of the inside of the brown mark can be seen.
Anti-welding (surface printing all kinds of color ink after the general green) did not see the number of layers, but in the circuit board of the non-effective areas of some manufacturers will have a digital sign.
He is a substrate, and then only the line, in the pressure on the PP and copper foil, and the original buy back to the same substrate, the difference is that he has a two-tier line, and then more in the same way to continue to do,
