Hi,
Thanks, I think we will just have to end up trying to solder it without soldering the centre pad, as some of the small pads of the QFN achieve a ground connection anyway.
The footprint pads emerge 0.3mm outside the QFN body outline all the way round.
We have got a hot plate but I am not convinced a great deal of heat will conduct through the 4 layer FR4 PCB. Some other components on the top side are already placed, as we needed to run the board manually (without the micro) first.
I don’t think we can find a syringe fine enough to deliver solder paste onto each separate pad.
We were wondering about just dolloping solder paste over the general pads area, and adding loads of flux, then put the QFN on, then just hot-airing it and hoping that the solder will un-short-circuit itself from between the pins…..and hope that the hot-airing doesn’t damage the PIC16F18856.