A circuit system is a physical entity attached to PCB, or by a dielectric layer between the dielectric surface of the metal traces (Trace) to interconnect components (including electrical and mechanical connection), the traces on different layers by electroplating vias (Via) connection.
In particular, high-speed PCB Multilayer PCB, often the number of metal layers (Plane) assigned to the medium between the power and ground (PoweriGnd) network. Such traces on the PCB can be roughly divided into two categories: microstrip and stripline. Only a microstrip line near the metal plane, usually located in the PCB surface (Top / Bottom Laver), can be divided into the surface of the microstrip line and cladding microstrip lines, surface microstrip traces directly exposed to the air, covered traces of the surface layer of the microstrip line covered with a dielectric film. Both sides of the flat metal strip line, electromagnetic radiation can be better prevented, according to the distance from the plane of the two strip lines, the strip lines can be divided into symmetric and asymmetric stripline.