PCB multilayer design technology, it can be said that multi-layer board and double-board design is almost, and even wiring easier.

You have a double board design experience, then the design of multi-layer is not difficult.

First of all, you have to divide the laminated structure, in order to facilitate the design, it is best to substrate as the center, symmetrical distribution on both sides, adjacent to the signal layer between the electrical layer isolation.

Layered structure (4 layers, 6 layers, 8 layers, 16 layers):

For the transmission line, the top and bottom layer using microstrip line model analysis, the internal signal layer with stripline model. 6 layer / 10 layer / 14 layer / 18 layer on both sides of the substrate signal layer is best to use software simulation, more trouble.

6 layer / 10 layer / 14 layer / 18 layer on both sides of the substrate is the signal layer, no electricity isolation, need to pay attention to the adjacent layer vertical alignment and to avoid the exchange loop.

If there are other power, priority in the signal layer to go thick line, try not to split the formation.

Next, ask the manufacturer for parameters (dielectric constant, line width, copper thickness, thickness) for impedance matching. These parameters do not have their own calculations (forget it is useless, manufacturers may not be able to do), should be provided by the manufacturers. With these parameters, you can calculate the line width, line spacing (3W), line length, then you can start drawing board.

Multilayer board with blind holes, buried holes, through the hole three, you can easily wiring, but the price is expensive. Sometimes need to reduce the thickness, in order to insert the PCI slot, and insulation media material does not meet the requirements (unless smuggled imports), this time can be used to non-uniform plate, for example: the middle 14 layers, edge 2 layer to solve, hey, that Expensive

High-speed line is best to take the inner layer, the top and bottom layer vulnerable to external temperature, humidity, air, not easy to stabilize. If you need to test, you can hit the test hole leads. Do not have flying lines, secant fantasy, multilayer board already do not need "hands-on", because the line in the internal and high frequency, can not fly, the line is not dense and can not drill. To develop the habit of paper operations, to ensure that a successful board, otherwise, in situ destruction of it, eyes do not mind not bother.