hi,
I’m doing a project using a nrf2401. I am doing the board layout and am wondering about the center pad on the chip. I think I can handle soldering the outside pins, but I’m not so sure about the paddle. I will be working with a circuit board made with a CNC milling machine. this board will not have plated through holes. Normally I just solder an old resistor lead through the holes.
It looks like the layout on the nrf data sheet has the center pad connected to ground. Is this required or is it just for heat? If not, would it be reasonable to put a dab of heat sink grease to connect with the board or is it critical that I have that pad connected to the ground plane on the bottom layer through vias?
I had a similar question. This is the answer I got from Nordic when I asked them about how their reference deisgns showed solder mask over the center ground pad:
The exposed die attach pad is a ground pad connected to the IC substrate die
ground and is intentionally not used in our layouts. We have left it unconnected
to avoid crosstalk from the GND pins carrying a multitude of frequencies back
into the chip substrate.
In our layouts we have not covered the GND vias underneath the nRF24xx with
solder mask, but feel free to do this in your design. All other signal lines
(e.g. VDD) must be covered.
Hope this helps.
Scott
thanks!
I thought it was strange that the data sheet does not mention this. Now, I see here that they told you to cover VDD lines with solder mask. too bad for me since we don’t have solder mask. I didn’t know that would affect anything actually. Now, I have a feeling that I’ll end up getting a printed board.