nRF52840 CKAA WLCSP Altium Footprint Not centered

[David Gomez]

Hello, 

I have just downloaded the NRF52840 Reference Altium Library. 

I have noticed that the step file for the component is not symmetrical about the origin. 

If I measure from pin A10 to the top, I get 0.269mm. 

From pin K10 to the bottom, I get 0.188mm.

Looking at the package drawing from the part documentation, I see no indication of this offset. The package appears to be symmetrical about the origin. 

Is the reference footprint incorrect? Or am I misunderstanding the drawing somehow? 

Thanks,

David

[Ressa]

Hi,

Your impression is correct, I could also check it on Altium reference design files . Regarding the package drawing, the distance from edge to ball is not presented . So it does not necessarily reject the observation you had. The total package dimension also gives similar impression, E is slightly bigger than D. 






       






Br,
Ressa