That's a.5 mm (20 mil) QFN. Trying to solder that with a soldering iron will only make a mess. Ideally you use solder paste, a stencil, accurate automated placement, and a reflow oven. I have soldered similar chips with a hot air station and some care. Use a soldering iron to put a bead of solder on all the pads. Take a few minutes to watch this amazingly informative video on how to solder QFN or MLF components without solder paste. The quality of the video and the information within is quite nice.
I do this pretty regularly at work, since we make qfn’s. I use a lab hotplate (with circuit boards bolted onto the sides to act as hand-rests so you don’t burn your hands on the top.) It works well at 200C. I put a dot of solder on the center of the DAP and put the chip on that, so I know that the DAP solder has reflowed when the chip drops down onto the outer pads. It works better if you use lead-based solder: enough capillary action to self-center the part. Also, Metcal sells one tip with an end radius of like 0.16mm, fine enough to touch the exposed metal on the sides of some QFN’s so you can reflow to the pad. Also also, you can often check continuity on individual leads by checking for the reverse body diode drop from a lead to ground. Also also also if you have a two-sided board, you can load the difficult parts on one side, then take a reasonably thick piece of aluminum plate and cut out holes where those parts live, and put the board face-down on the plate on the hotplate and load qfn’s on the topside as well.
I do this pretty regularly at work, since we make qfn’s. I use a lab hotplate (with circuit boards bolted onto the sides to act as hand-rests so you don’t burn your hands on the top.) It works well at 200C. I put a dot of solder on the center of the DAP and put the chip on that, so I know that the DAP solder has reflowed when the chip drops down onto the outer pads. It works better if you use lead-based solder: enough capillary action to self-center the part.
![Solder Solder](http://www.aimsolder.com/sites/default/files/techtips1.jpg)
![Solder Paste Qfn Solder Paste Qfn](/uploads/1/2/5/4/125428263/606450447.jpg)
Also, Metcal sells one tip with an end radius of like 0.16mm, fine enough to touch the exposed metal on the sides of some QFN’s so you can reflow to the pad. Also also, you can often check continuity on individual leads by checking for the reverse body diode drop from a lead to ground. Also also also if you have a two-sided board, you can load the difficult parts on one side, then take a reasonably thick piece of aluminum plate and cut out holes where those parts live, and put the board face-down on the plate on the hotplate and load qfn’s on the topside as well.