Un bel giorno Joerg digitò:
Is it reasonably possible to solder a bypass cap to adjacent pins on a
> 0.5mm pitch QFP chip or would that just open up a can of worms?
If the pin are adjacent, it should be quite easy and clean if you use hot air and very small capacitors.
Anyway, if you really need 0.1 uF caps, it's not necessary to solder them directly on the pins. It's enough to solder them below 2-3 cm from the chip. There is a very nice application note on the Xilinx site about bypass caps:
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