Is it feasible to do reflow with hand-applied solder paste instead of a stencil? I want to solder a adxl335 package accelerometer (no pins, just pads on bottom like QFN). It may not be ideal, but it would work good enough, right? Thanks.
I'm not sure a stencil has any inherent advantages over using a syringe/dispenser type except when the number of pads that need solder is large, and there is a need to get things done quickly.
I'm inclined to think that, for a small-pitched package like yours, a stencil might smear the paste, and that doing it manually would be more accurate (unless your hands are shaking from too much caffeine!).
BUT I don't have any evidence to back this up, so please, those of you with layout experience, correct me if this is wrong.
I have alot more luck with a syringe than the stencils. On a PCB board with around 20 components, a few of them small pitch, I could do the syringe faster and with better results. I had problems with the solder not sticking to some pads and smearing on others. I am sure with more practice it would have gotten better yet I really took to the syringe route quickly.
I keep my solder syringe in the freezer. Its atleast a year old and works great.