Electronic – How do i solder qfn package using soldering iron

hot-airqfnsolder-pastesolderingsoldering-iron-station

I don't have any soldering station but I need to solder the qfn package chip so how I solder it using a normal soldering iron.

Best Answer

If the PCB has not had any parts mounted on it yet (or at least none on the bottom) you could try a skillet. Dispense solder paste/flux, place the part, and heat until it melts. I have not tried this personally (normally I use a solder paste stencil and reflow oven). Of course you should not use the skillet for food ever again, particularly if you use lead-based solder, but even the flux may not be especially healthy.

Hot air is another way, but be careful with a cheap uncontrolled heat gun, it's pretty easy to fry FR4 let alone the chip with a $10 paint stripper heat gun (at least I found that).

If you don't have solder paste you might be able to get away with tinning the pads, applying lots of liquid flux to the chip and to the pads and heating it until the chip settles down into position. If you've designed the pads according to recommendations and placed the chip close to the correct position it should be pulled into alignment with the pads by surface tension of the solder.