Electronic – The Thermal relief consideration for TVS diode (for ESD protection)

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I am designing a print which has some mircofit connectors, I have placed TVS very close to the connectors on the print and the ground pad connected with a GND polygon directly, this polyon connects with a ground layer by GND vias.

My question is, since the ground pad of the TVS diode connects to the a copper plane directly, do I need to use thermal relief connection between the GND pad and the copper plane like below? enter image description here

I knew that TVS diode is used to shunt the ESD current, so i am expecting when ESD happen, there is a huge current goes through the TVS diode for a very short time, according to IEC 61000-4-2, almost 30A current in 800ps (90/10 rise time), if a thermal relief is needed, how do I use these information to calculate the trace width and air gap for the thermal relief connection?

My last question is if the other pad of the TVS diode, which connects with the ESD source can be soldered easily(also shown in the pciture), do I still need to care about the GND pad?

Thank you very much!

Best Answer

You don't need to but it makes soldering easier.

Inductance is what matters more for ESD than resistance so the dimensions aren't too big a concern.

My last question is if the other pad of the TVS diode, which connects with the ESD source can be soldered easily(also shown in the pciture), do I still need to care about the GND pad?

Huh?