I've got some really tiny leads on a USB port that I need to solder to a board.

SMD mini USB port

The local Hackerspace has a microscope that I'm going to see about using this for, but even a soldering iron is gigantic compared to these tiny leads. Does anyone have any tips (pun intended and unintended) for soldering these leads to a board?

  • \$\begingroup\$ There is bound to be someone at the hackspace who can show you how to do this. \$\endgroup\$ Feb 11, 2011 at 10:49
  • \$\begingroup\$ What about hot air soldering? youtube.com/watch?v=s49dIm0LX5I \$\endgroup\$
    – leeand00
    Feb 23, 2011 at 2:26
  • \$\begingroup\$ @mikeselectricstuff Nope it shutdown, and there was nobody there who knew how at the time... \$\endgroup\$
    – leeand00
    Aug 19, 2011 at 18:09

3 Answers 3


Flux! Use plenty of flux and it will magically work.

You don't need:

  • a super-skinny soldering tip

  • hot air station

  • very thin solder

  • solder paste

  • desolder braid (helpful though)

You do need:

  • Flux

  • Magnification (you've got that covered)

Flux up the pads really well, then apply heat and solder. Try to make a big ball that covers all the pads. Then remove solder by repeatedly cleaning the tip and touching it to the pads. This technique is similar to drag soldering. If in doubt add more flux.

  • 5
    \$\begingroup\$ While I mostly agree that you don't need fancy equipment to do this, I disagree on two points. First, tons of flux doesn't do a job better than a proper amount, it just makes the work area messy and gives you a bigger cleanup job. Second: I prefer a smaller soldering iron tip (I think the one I use for most of my soldering is a Weller 1.2mm conical tip) and I do use very thin solder. No, you don't need super fancy stuff, but it's helpful to have tools that are about the right size for the job. :-) \$\endgroup\$
    – akohlsmith
    Feb 10, 2011 at 20:32

I would recommend a hand-held hot air rework tool (like the Hakko 851) to gently heat the whole PCB area and allow the part to reflow into place.

You may find that using a conventional iron to 'tin' the pads before using the hot air tool will be necessary, if you don't have a stencil and solder paste to properly prep the pads. Just make sure (with the microscope) that there aren't any solder bridges before you introduce the connector.

  • 1
    \$\begingroup\$ There are very, very few things that require hot air. This really isn't one of them. \$\endgroup\$
    – akohlsmith
    Feb 10, 2011 at 20:33
  • \$\begingroup\$ I'm used to air-soldering 0603, 0402 and MSOP parts. I find that the solder joints are more reliable with the hot air tool than with an iron. \$\endgroup\$ Feb 10, 2011 at 21:36
  • \$\begingroup\$ @Madmanguruman: This method could be of use to my current task. Is your method roughly the following?: You use the soldering iron to run a line of solder across all the pads (I suppose bridges are fine at this stage). Place the part, using tweezers to hold it in place over the solder-covered PCB pads. Then run the hot air gun? \$\endgroup\$
    – boardbite
    Apr 5, 2013 at 7:51
  • \$\begingroup\$ @Inga Indeed it is. \$\endgroup\$ Apr 5, 2013 at 12:00

I use a cheap stereo dissecting microscope with a fine tip Metcal cartridge for jobs like that.


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