What is Fiducial

What is Fiducial

A fiducial refers to a fixed reference point or marker strategically placed on a printed circuit board for alignment and positioning purposes. Fiducial markers are crucial in automated electronic assembly processes, particularly in SMT applications.

Fiducials serve as visual cues for indexing systems and vision systems, allowing them to accurately orient the PCB and precisely insert components onto the circuits. These markers typically consist of a solid copper ring on the PCB’s copper layer, a circle in the solder mask for alignment, and an optional text label for additional information or identification.

Global fiducials are arranged in an “L” shape on the PCB and panel edge, while local fiducials are recommended for components with a small pin distance. The coordinates of fiducials are indicated in the Pick & Place file, and they may also be indicated in the solder paste data for stencil production.