Getting ESD discharges onto a connector to chassis

[Northy]

Hi all,

This has come from another question I've been asking about GND and Mid-Plate GND pins on a USB Type C connector.

If I'm putting something in a metal box in the past I've always connected the 'chassis' of the connector to a Chassis GND pour (via stitched on multiple layers) around the edge of the PCB and tied this back to Mains Earth. The thinking being to get any ESD events back to Earth Ground as fast as possible, to try and persuade it from not going onto the main circuit.

Now the USB Type C connector has a shield and GND pins, but the spec says these are all tied together in the connector plug, so my usual way of doing things won't be as effective.

I know these things are not black and white, and I'm more than willing to test what is needed at a test house, but what 'things' would it be sensible to add pads for on the PCB to connect GND to Chassis near the connector (to again try and persuade the ESD event to go to the chassis) and would that be a suitable strategy to try and control the path of the ESD strike?

I do have audio circuitry on the board so I'm reluctant to simply tie all the GNDs together, it seems far more normal (and actually required for good performance) to connect Chassis GND to the PSU GND (0V) only at one point right near the PSU connector.

Thanks,

G