Advise on soldering tiny SMDs

Hello, I need to use a potentiostat to use with a Carbon Monoxide sensor and will need to use LMP91000 potentiostat which has 14 pins, 0.5mm pitch.

Any advise as how to solder this part on a breakout board? solder paste or another technique?

Thanks, B.

Solder paste and a hot air gun - but get it all lined up accurately first...



A really tiny soldering iron?? :)

There are a few ways to handle it. Myself, I use a small amount of solder paste (like put it on with a tip of an Xacto blade), position the chip so each lead makes decent contact with the solderpaste, and while holding the part down, run a solder gun down the pins. If you overdid the paste and have bridging between pins, use some solder wick and flux to clean it up. Check your work out with magnifying lenses to make sure you are not shorted.

If you are going to regularly do small smd's, you might check out a hot air rework station. It makes life easier.

If you don't have any paste, you can also flux the pads, use solder to make small beds on each pad, flux the leads of the chip and set it on the pads and run the solder iron over them too.

YouTube "drag soldering"

That's their way to do it. It's why I'd rather solder soic than dip. It's like magic, there's a puff of Smoke and the joints are soldered.

Also make the pads extra long, so you can heat the part under the pin by conduction.

0.5mm is very fine pitch, you need a bare minimum of solderpaste, a proper breakout board with solder mask, and use a hot-air station or an oven. Dragging will likely short out all the pins unless you have really good skills, and will not solder the thermal pad in the middle.

I have soldered 0.5mm pitch ICs with a normal iron and small tip. Just solder each pin and don't worry about shorts. Then when it is soldered use solder braid to remove the shorts. I have soldered many a 80 pin quad flat package with this technique.

Hi, You can use microscope to enlarge the vision to align all the pins properly. I have done soldering on the micro controllers using tiny solder and enough of the solder paste added to it. make sure all the pins are properly in contact after solder..

Watch this:

Much good advice in general plus showing how to solder using different hand-soldering methods. He doesn't produce the best hand soldering visual appearance, but he gets it done and offers plenty of explanation along the way.

If you don't want to watch the whole video, here is the part about 0.5mm SMD chip specifically: It is only 5 or 10 minutes long if you just watch the part specific to your question and is well worth the watch.

If manually doing this is a 'no-go' for you...

maybe invest in a vinyl plotter/cutter.. and start making your own solder paste stencils/masks..

(thats what I do.. and help when I need to make more then 1 of the same board at a time)

lay down the stencil smear your solder paste remove stencil populate board with components.. throw it in a cheap toaster over @ around 200+ degrees... and wait for 3-5 minutes.. waiting for the paste to re-flow.

  • I used a $17 non-modded toaster oven from my local wal-mart