The ATTiny406 is in a QFN-20 3x3mm square package with 5 pads per side. I don't know what this is some kind of LGA but it is not the correct footprint for this part!
Added 8 months, 1 week ago.
Hello. Thanks for waiting! We have updated this part for you. You can download it in the following link. https://www.snapeda.com/parts/ATTINY406-MFR/Microchip/view-part/?ref=search&t=ATTiny406