Printed circuit boards (pcb) are conductive paths located on an insulating substrate with the role of connection between different electronic components.
The term "controlled impedance" refers to the electrical interconnection paths between electronic components that present a constant impedance when propagating signals.
The impedance depends on the path geometry and the electrical permittivity of the substrate.
Stack-up printed circuit boards 4 layers
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Layer Top |
Stack-up printed circuit boards 6 layers
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Layer Top |
Currently, the production and assembly of printed circuits are automated. Electronic computer aided design software is available to do much of Controlled impedance the layout work. Multilayer PCBs allow for much higher component density because the component paths on the inner layers would occupy the space between the components. The increase in the need
PCB are usually printed with a non-conductive permanent epoxy ink. The color is usually white, although other colors are available: yellow, black, blue, red. Screen printing is used to render useful information on Controlled impedance the PCB board that can help users during assembly. It is used to mark component values, part numbers, test points,
of the tracks and the distance between them, i.e. the insulation. For a multilayer printed circuit with a specific stack-up, it must Controlled impedance be taken into account that the 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
