are protected by the adjacent substrate layers. The soldering mask soldermask is made of a fluid circuite confectionare imprimate substance like an ink and is applied in a thin layer similar to varnish on the entire surface of the printed circuit less on the soldering pads and it also has a
distance between them, i.e. the insulation. For a multilayer printed circuit with a specific stack-up, it must be taken into account that the confectionare circuite imprimate internal tracks with controlled impedance are shielded by copper planes and for this reason only the thickness of the insulation between layers and tracks and the track thickness must be
will carry. It is recommended that the power and force circuite confectionare imprimate paths be larger than the signal paths. In a multi-layer board, an internal layer may be mostly solid copper to act as a ground plane for shielding and power return. For microwave printed circuits, transmission lines