Optimizing PCB space with footprint size

[Mishka]

Hi,

looking to nRF52832 reference PCB designs I've noticed that BOM contains different element sizes for different packages. Such, most of capacitors for QFN48 have 0402 footprint, when WLCSP suggests 0201. The same for crystals. So I'm thinking about saving some space with smaller packages.

It's reasonable to avoid extra work recalculating the matching network and keep it intact. Also, replacing the 32MHz crystal (which itself is of the same footprint) capacitors won't really change anything:

But how about other elements? Would it be safe to follow WLCSP BOM as a packaging guideline?

Also, for my understanding moving them won't affect RF performance, right?

Thanks!

[Kaja]

Great Mike! 

We can help with tuning and RF measurements, it's a service we provide, you just have to cover the shipment cost. 

So if you want you can send me two or three working PCB's and an sample enclosure, and I can do the measurements and tuning for you, when you have produce some boards.

Best regards,
Kaja

[Mishka]

That's simply outstanding, thank you so much! I'm going to manufacture this board first, it's required for the second one. And after I'll be done with them both I'll be very glad to fine tune the radio. Thanks again!

[Kaja]

Your welcome, 

shipping information: 

Mark the packet with the case ID(232469) and send it to:

Nordic Semiconductor 
Att: Kaja G. Sørbotten 
Otto Nielsens vei 12
7052 Trondheim
Norway

Just give me a heads up, when your sending it. 

Best regards,
Kaja