Fiducial Marker
What Are Fiducial Markers?
Fiducial markers (fiducials) are small, precisely defined copper features placed on a PCB that serve as alignment reference points for automated assembly equipment. Pick-and-place machines use machine vision cameras to locate fiducial markers on each board, establishing the exact position and orientation of the panel or individual board before placing components. Without accurate fiducials, the pick-and-place machine cannot compensate for panel-level or board-level registration variations, leading to component misalignment and assembly defects.
There are two types of fiducials: global fiducials (placed at the corners of the board or panel to establish overall alignment) and local fiducials (placed near fine-pitch components like BGAs and QFPs to provide localized alignment accuracy). Fiducial design follows specific conventions — typically a 1mm diameter round copper pad with a 2mm to 3mm solder mask clearance to create high visual contrast for the machine vision system. Fiducials must be placed on solderable surfaces with the appropriate surface finish and must not be obscured by silkscreen or solder mask.
Assembly-Ready Fiducial Placement
Proper fiducial placement is an often-overlooked aspect of PCB layout that can cause significant assembly delays when missing or incorrectly specified. AI-powered layout tools that incorporate assembly requirements during generation can automatically place global and local fiducials according to the target assembly equipment's specifications, ensuring that every generated design is ready for automated placement without post-layout manual additions. This attention to assembly infrastructure details reflects the broader goal of producing not just electrically correct layouts, but fully manufactureable designs.






