NRF54 QFN48 Exposed Pad Vias

[zachf]

Hello,

For the vias in the exposed pad of the NRF54L, I've read that ideally, the vias should be capped and filled. However, due to trying to minimize cost, I was wondering if Nordic has any guidance/recommendations for using unfilled and uncapped vias in the pad? I.e. via size/solder paste placement? I understand that this would be a sub-optimal deviation from Nordic guidelines, but I want to avoid the extra cost of via-in-pad usage for prototype designs. Thank you!

Best,

Zach

[JONATHAN LL]

What package type are you going for? For the QFN package there are other criteria that also are important like the PCB stack up and we have recommendations for that as well.

In general the downsides to going with open holes here is that the solder can escape and cause poor solder joints and this will likely increase the likelihood of issues under production.

So we only recommend via Type VII as these gives the best reliability. 

If you choose to deviate from this we can try to help and guide but it will come with limitations and you will have to decide if the potential issues and possible performance loss is worth the possible cost reduction. 

Regardless I recommend that you ask for a design review from us so that we can have a look and provide proper comments everything we related to our products and the antenna\radio implementation. 


I would recommend a close relation to the manufacturer to make sure the process and production is as reliable as possible for the product, and follow the recommendations they provide for best success rate. 


Regards,
Jonathan