How to Solder SMD / SMT Components With a Soldering Iron





Introduction: How to Solder SMD / SMT Components With a Soldering Iron

Surface-Mount Technology (SMT) and Surface-Mount Devices (SMD) are essentially just tiny little components that are soldered to the surface of the PCB, not through it like many larger components. The Radio-Electronics website and, of course, Wikipedia, have some good overviews of these kind of components.

The purpose of this Instructable is to show how I've successfully soldered some SMD components without any special tools, and to show some techniques you can try. I am not an expert; I'm simply a hobbyist without training; I appreciate all constructive feedback and tips in the comments below!

These pictures were taken as I assembled an ATMEGA328P based Transistor Tester - which I have documented in full, here:

I thought a more focused Instructable might be helpful for those wanting only this specific information. automatically compresses the pictures in the Instructable. Viewing the full sized picture may be more helpful in some cases; just click the picture, click it again, and you should see a way to view the "original image".

**Edit - 3 OCT: Be sure to read through the comments for additional great tips and pointers!

Step 1: The Solder and Soldering Iron Tip

Step 2: Cut Tiny Chunks of Solder

Step 3: Pick a Piece of Solder

Step 4: Place the Piece of Solder

Step 5: Melt the Piece of Solder

Step 6: Place the Component

Step 7: Solder the Component

Now it is fixed in place!

Step 8: Place Next Piece of Solder

Step 9: Solder the Next Leg!

Step 10: Inspect the Contacts

I'll provide one more example below, but this is basically how I've done it.

Step 11: Repeat the Process!

Step 12: The Next Completed Piece

And this concludes the Instructable. I hope it is helpful for your projects!~



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I recommend investing in a cheap hot air station and some quality solder paste and flux.

I probably will one day, but this instructable was to show a technique for simply using a soldering iron. I do need to get some flux and learn how to use soldering paste, but i've not yet done that. I hear it makes things easier!

I've soldered components with solder paste and hot air and it's really easy, the solder melts and components just stick into place. For IC's with many legs it's also a really fast process.

A few tips:

i) For very small smd, and those with earth pads underneath I use a temperature controlled heat gun (Bosch PHG 630 DCE) set to 320 degC and solder paste. I apply the gun to the underside of the board until I see the solder paste melt and then finish off with a bit of heat from the top.

ii) You often end up with bridged pins after soldering. Clean the soldering iron well and wipe it across the pins so that is picks up the excess solder and removes the bridges

iii) These small chips are easier to handle if you first solder them to a DIP adaptor e.g. or search "smd to dip adaptor" on digikey.

Any idea, where I would get a 100pin smd to dip adapter (Its for a C8051F020)

Go to digikey, enter smd to dip adaptor in the search bar and then, when Adapter, Breakout Boards page shows up, click in the "No of Positions" filter col. scroll down and click on 100

You sir, are a legend and I thank you :)

Great tips, thanks! I'll look into the DIP adapter idea, sounds helpful.


I´am sorry to say , but you have way too mutch solder on you transistors or IC, it should never end up on the upper side. this will remove the flexibillity in the legs of the component.

Thanks, I'll look into that. What do you recommend to fix it? Cut smaller pieces? Or wick/desolder it?