nRF52840 pcb - through hole via

[wallance.lin]

Hi

regarding the Nordic guidelines for aQFN, it recommends to use 0.305/0.61 for through hole via.

We are using 0.2/0.4 to avoid soldering bridge and non find any issue after several times production.

we still need the help from Nordic, do you have any concern or recommend for it?

Best regards

Wallance

[ketiljo]

Smaller vias are no problem, if your PCB manufacturer are happy with it. 

[wallance.lin]

Hi

thanks!! we also adjust the land pad design to keep all them are 0.275mm.

it doesn't follow the guideline, may I have your help to check if any concern for it?

[ketiljo]

For a aQFN pad size od 0.25 mm, the recommended PCB land pad size is 0.275 mm, with a solder mask of 0.375 mm and a stencil opening (paste mask) of 0.3 mm. 

[wallance.lin]

Hi

the distance between two pads is only 0.125mm when we follow the guidelines. it will be increased to 0.225mm when we keep them are 0.275mm. it is better to avoid soldering bridge from production view. May I have your help to advise if any risk to impact the IC performance or something if we would like to keep current setting?  or where we need pay attention if we would like to keep it. thanks!

[ketiljo]

That should be fine.