https://devzone.nordicsemi.com/f/nordic-q-a/52590/how-to-replace-resolder-nrf52840-manually-qfn-73Hi all! Resoldering usual QFN packages with pins along the edges is not such a big problem... but how is this usually done with devices they have pins underneath the package? (Like nRF52840&#39;s QFN 73 package.) I need to replace/resolder some nRF52840en-USTelligent Community 13Thu, 26 Sep 2019 08:05:13 GMThttps://devzone.nordicsemi.com/thread/211964?ContentTypeID=1Thu, 26 Sep 2019 08:05:13 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d3d7cb81-b225-4dd0-9d3e-28ad9b685ef9ketiljo<p>You can use a stencil that&#39;s cut to size so it fits where the chip normally is. But that can be fiddly if the surrounding components are close. Probably better to apply paste to the chip directly, from the underside of the stencil, and place the chip carefully on the PCB and re-flow.&nbsp;</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/211896?ContentTypeID=1Wed, 25 Sep 2019 15:53:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:0bfe313e-ddff-4b77-8dc6-b09b5b82d627awneil[quote userid="71182" url="~/f/nordic-q-a/52590/how-to-replace-resolder-nrf52840-manually-qfn-73"]QFN packages with pins along the edges[/quote] <p>You mean QF<span style="text-decoration:underline;"><strong>P</strong></span>?</p> <p><img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/pastedimage1569426706364v1.jpeg" alt=" " /></p> <p><a href="https://en.wikipedia.org/wiki/Quad_Flat_Package">https://en.wikipedia.org/wiki/Quad_Flat_Package</a></p> <p></p> <p>QF<span style="text-decoration:underline;"><strong>N</strong></span> =&nbsp;Quad Flat <span style="text-decoration:underline;"><em><strong>No</strong></em></span>-leads:</p> <p><img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/pastedimage1569426762165v2.jpeg" alt=" " /></p> <p>/<a href="https://en.wikipedia.org/wiki/Quad_Flat_No-leads_package">https://en.wikipedia.org/wiki/Quad_Flat_No-leads_package</a></p> <p><span class="mceItem mceNonEditable mceQuote" id="mceQuote0">...</span></p> <p>Sounds like a job for a specialist, to me ...</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/211879?ContentTypeID=1Wed, 25 Sep 2019 14:39:35 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e9a1b090-1dc4-4176-9b7b-242b858b736bd.s.<p>Sounds obvious but how to get solder paste on the pads? I can&#39;t use a solder paste stencil anymore because the pcb is already assembled.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/211854?ContentTypeID=1Wed, 25 Sep 2019 13:30:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d3f56b7c-d138-49bc-b1db-070f6f236881ketiljo<p>Hot air or reflow oven. Same as BGA, CSP etc.&nbsp;</p><div style="clear:both;"></div>