What is Fiducial Mark
A fiducial mark refers to a symbol or reference point placed on a PCB layout. It is a tool for automated machinery, such as pick-and-place machines and optical inspection systems, to accurately place components or scan the PCB. Typically, a fiducial mark is a circular pad of exposed copper that is distinct from other landmarks on the PCB.
Fiducial marks help ensure the correct alignment of components during the assembly process. By providing a standardized and easily recognizable reference point, the machinery can determine the precise location of components. This helps to reduce errors and improve the efficiency and accuracy of PCB assembly.
There are two types of fiducial marks commonly used in PCB designs: global fiducial marks and local fiducial marks. Global fiducial marks are usually placed near the corners of the PCB or on panelization rails, while local fiducial marks are placed around specific components that require higher accuracy, such as fine-pitch QFPs, QFNs, and BGAs.