NC pads can't be easily routed through

A ESD protection device (TPD4EUSB30) has 4 NC pins which has no connection internally(and marked NC in symbol files), however when doing signal layout, these pins could be connected with corresponding signals on the opposite side(as described in datasheet page 16).

I wonder there is any way to route these pads without modifying symbol nor manually routing without interactive router/DRC, any advices appreciated. Thanks in advance.

The symbol you list is for a different device than the datasheet you link to. The datasheet assigned to that symbol does not show this usecase as clearly as the datasheet you link.

One can easily argue that the symbol is badly made (might even violate the KLC). The pins should definitely not be made invisible as there is a usecase where these need to be connected (Quite well shown in your datasheet, not as clear in the original). And one might even argue that giving it the type “not connected” is wrong as i guess this usecase might be quite common.

You have two options going forward. Use the symbol as is and connect to the invisible NC pins (will give you false positive ERC warnings and might make your schematic hard to read)
Or create a symbol with these NC pins set to visible and pin type passive in your personal lib.

I took the liberty and reported this already over on the lib repo:

Thank you for the quick reply and apologize for my careless mistake.
I finally decided to make my own symbol, and maybe submit a PR with this new device after this issue has been addressed and clearfied.

KiCad allows multiple pins of the same number in a footprint, and they all connect to the same net.
Thus you could modify the footprint, to make NC.D1- the same pin number as D1- (etc)

Or, you could modify the footprint to remove entirely the NC pins, so they have no pads and no paste.
That would need production testing, The part is symmetric and there is a GND pin still present to ‘stick’ down that side during reflow.

I really advice against hacking this on the footprint side. It is really not worth it. Making a new symbol does not take long enough for this to pay of in any way.

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