Video Blog #025 - QFN Reflow Repair
DISCLAIMER: This video is educational only, so if you decide to do the same yourself then you are on your own, I can't be held responsible for any problems/issues/damage/injury that may occur if you decide to follow this blog and try it yourself.
A quick 5-minute video demonstrating my technique for QFN IC SMD package repair on a circuit board that I had just reflowed in my oven but that had resulted in some short circuits.
QFN packages don't have legs, the solder pads are on the underside of the IC and don't extend onto the sides of the IC so in effect the package sits over the pads and thus makes it quite hard to clear any short circuits because you don't have full access to the solder from all sides like you do on a regular external IC pin.
In my case the short circuits were most probably created by using too much solder paste with the stencil, I knew this at the time but rather than clean off the board and start again I just relied on fixing the problem later as per the video.
Flux pen used = Kester Flux-Pen 951 Rosin Flux, Type RMA
I have also used other types of flux, such as:-
- VersaTech No Clean Liquid Flux
- Amtech Flux Paste RMA-223-TF