We are using TVS diode, part no "TPD1E10B06DPYR" for ESD mitigation for medical device. We are following the IEC 60601-1-2 standard, sub clause IEC 61000-4-2. The maximum test voltage is +/-15KV (bipolar). We are passing +/- 8 KV test, but failing in +/- 12 & +/- 15 KV test (air discharge). The applicable test is air discharge, whenever the ESD probe was coming near conductor base sheet (below volume potentiometer) and near the thin wall of the switch (see fig. 1 below). I heard the discharge sound and the device used to stop function and then we had to manually re-start the device.
Should we put TVS diode across conductor base plate and the ground and across the wire of the switch to the ground. Will the TVS diode work in this case, arrest the voltage.
Does two layer and four layer PCB layout will have any effect.
Pl suggest for the best possible outcome, for passing +/- 15KV ESD test (air).