ESD test

 I have heard a lot of complaints about ESD damages on keyboards. Today TVS diodes work excellently, so we do not hear such complaints nowadays. But ESD is still a severe threat for the product quality. I tested Nanaju prototype by IEC 61000-4-2:2008 standard.

The result is, it passed for level 3 (contact discharge: 6 kV, air discharge: 8 kV), and failed for level 4 in air discharge (15 kV).

I will analyze the failure mode, but I think that the ESD immunity of Nanaju will not become much better. The design does not allow bigger / more components nor larger track gap. Nanaju will not be super tolerant to ESD, sorry.