What is Edge Plating？

In the PCB industry, edge plating, sometimes called Castellation or Side plating, refers to the metallization of the edges of a circuit board. In other words, side plating refers to the copper plating that runs from the top to the bottom surface of the board and along one or more peripheral edges. The surface treatment for side plating can be ENIG, ENEPIG, HASL, or any other surface treatment that provides electrical connectivity. With side plating of printed circuit boards, the PCB edge is used for technical features of the later assembly. Portions of the PCB's outline and interior areas can be metalized.

How to Design Edge Plating for PCB?

To ensure the manufacturability of edge plating, overlapping copper (i.e. copper surfaces, pads or traces) should be used to define the metalized areas in CAD layout file. The following rules should be followed:

  1. The minimum overlap value should be 0.5mm.

  2. For the connection layers, a minimum of 0.3mm of a connecting copper line must be defined.

  3. On non-connection layers, the copper should be kept at least 0.8mm apart from the edge of outer contour.

Applications of Edge Plating PCB

Edge plating has a variety of purposes. PCBs with edge plating are widely used in many industries, including but not limited to the following areas:

  1. Edge soldering

  2. Board-to-board connection

  3. Increased current carrying capacity

  4. Housing connection

  5. Improvement of EMC performance