PCB based USB ESD protection / filter?

[ubbut]

Just watched Dave's 3000T oscilloscope teardown and one detail on the board caught my attention.
(It is not visible in the high res photos, so I am attaching a screen shot from the video)

The USB lines have this interesting PCB feature. Given that the only other part here is (presumably) a common mode filter,  I suspect that this acts like a tiny spark gab for ESD protection. But there may be more to it as there are these 'wiggles'. Maybe this is some LC-Filter as well?

I would be very interested in learning more about this. After all you get PCB features for free

thanks

[T3sl4co1l]

Doesn't look like much of anything with silk and soldermask over it.

Tim

[BrianHG]

That's not silk paint.  It's too fine and exact to the trace thickness.  It is exposed tin plating.
Also, look at the other USB plug, it has the same pattern, with traces to the GND plane and decoupling cap.

[ubbut]

I agree. This means there is some purpose here. Would really be interested in design parameters and insights !

[whollender]

Only going by the copper, it looks like it's just a footprint that's not loaded that's a shunt between the line and ground.  In that location, I'd guess for ESD.

That doesn't explain the opening in the solder mask, however.