https://devzone.nordicsemi.com/f/nordic-q-a/97463/pre-tin-a-qfn-chipHello, we use the nRF52840 in the aQFN 73 package, 7 x 7 mm. Seeing some production failures with the boards. Examined several boards under robotic X-ray and there are several questionable solder joints around the nRF chip. The assembly house is recommendingen-USTelligent Community 13Wed, 08 Mar 2023 14:53:32 GMThttps://devzone.nordicsemi.com/thread/414182?ContentTypeID=1Wed, 08 Mar 2023 14:53:32 GMT137ad170-7792-4731-bb38-c0d22fbe4515:374d0a5f-6614-455f-89ab-50e6602e34dcketiljo<p>Hi MIchael</p> <p>I have never come across the need for this before. I suggest that they check the solder profile and amount of solder paste on the pads first. Please take a look at this whitepaper:&nbsp;<a href="https://infocenter.nordicsemi.com/topic/nan_040/APP/nan_040/nan40_intro.html?cp=17_">https://infocenter.nordicsemi.com/topic/nan_040/APP/nan_040/nan40_intro.html</a></p> <p></p> <p>Best regards,</p> <p>Ketil Aas-Johansen</p><div style="clear:both;"></div>