How to Add Edge Rails and Fiducials for PCB Assembly Orders

Overview

Edge rails and fiducials are required for standard PCB assembly at JLCPCB.

Edge rails are added to increase the clearance between components and the board edges. Fiducials are small reference pads placed on a PCB to assist Pick & Place machines in accurate component placement. They are often added on edge rails as well.

To achieve optimal assembly results, we recommend following the guidelines below when adding edge rails and fiducials to your PCB design.

Edge Rails

Edge rails are added to increase the distance between components and the board edge. The minimum width of edge rails should be at least 5 mm.

Note:
By default, assembled PCBs will be delivered with edge rails attached. If you would like us to remove the edge rails after assembly, please inform us when placing your order. Additional post-processing fees will apply.

Fiducials

1. Fiducial markers are created by placing an un-drilled circular copper pad on the PCB. The fiducial area must be free of solder mask.

2. The recommended diameter of a fiducial marker is 1 mm. The solder mask opening should be twice the diameter of the exposed copper pad.

3. Three to four fiducial markers should be placed along the board edges to ensure optimal placement accuracy.

4. Fiducial markers must maintain a minimum clearance of 3.35 mm from the board edge, including the fiducial keep-out area.