PCB edge plating
PCB edge plating is the process of connecting the top and the bottom of the PCB by electroplating around the outer edges of the PCB. This process also can be named as sideplating, border plating, edge metalizing, or plated contour. For the devices with moderate or high requirements for EMC, signal integrity, and heat dissipation, edge plating has apparent advantages at negligible cost. Usually, ENIG or nickel-gold is recommended to be the surface finish method for the edge plating.
The comparison of PCB with edge plating and PCB without edge plating
The benefits of PCB edge plating
1. Prevent electromagnetic radiation from radiating or leaking to the edge of the board.
2. Improve PCB’s EMC performance
3. Provide excellent signal integrity
4. Cooling function to help thermal dissipation
5. Achieve board-to-board connection and housing connection
6. As an edge connection and protection
7. Improve the manufacturing results through edge soldering on the plated side
8. Improve the capability of PCB current-carrying
Issues that need to pay attention to edge plating
1. Overlapping copper should be used to design the metalized areas in the CAD layout to ensure the productivity of edge plating. The minimum overlap is 500mm.
2. Ensure long-term adhesion of all the layers by preparing smooth edge surface and suitable plated material.
3. Avoid burrs as much as possible.
4. Metallization cannot be performed at the location of the small bridge.
5. No internal power planes get to the board edge.
6. Ensure enough space on edge for side plating.
7. Layout the board outline where the edge plating is required before through-hole plating, which can avoid cutting marks during the V-cut process.
8. The area that needs edge plating should be marked clearly in the mechanical layer before fabrication.
Edge plating helps to create a robust connection of the PCBs and can reduce the chance of device failures. Therefore, edge plating is widely used in applications where connections need to be better supported and becomes a common practice in PCB manufacturing.