Learning how to solder with hot air and solder paste is definitely one of those skills that you need to practice in order to built and fix modern electronics. The perceived difficulty of soldering SMD components has scared me in the past and has prevented me from learning more skills like PCB design, because why design a board if you cant assemble it!
But no more, I was determined to start learning and practicing SMD soldering using both the regular soldering iron and the hot air gun. I also decided to play with solder paste for the first time as well.
I created a small video of my first time assembling a PCB using these methods that I have learned so far.
Tools
The tools I used for this were not super expensive but you will need to purchase a few things to get started. All of the below you can get off of Amazon, just click on their respective pictures to check them out.
Hot Air Gun
I purchased a really cheap model off Amazon that I have linked below. You can pick this up for around $35 if you get your timing right. It comes with 3 different nozzles and has a dead-simple user interface for setting the temperature and airspeed.
Stick Vice
Keeping the PCB from sliding around your bench is an absolute must when SMD soldering. The Stick Vice is somewhat of a cult classic in electronic hobbyist circles as it’s super rigid, easy to use and position, and it has replaceable jaws! It’s around $30 but it will save you many headaches in the future! You can pick one up on Amazon as well by clicking on the picture below.
The company that makes the Stick Vice also provides STL files for the jaws so you can print them at home if you really need a pair ASAP!
Tweezers
I was not able to find the tweezers that I use online but have linked some nice ones from iFixit that should do the job. These will be necessary to place your components on the PCB as well as to adjust components during reflow if they move out of place.
Solder Paste Syringe
Solder paste can come in a wide variety of containers so you need to be aware of what you are buying if you want to hand assemble your board. Some of the syringes do not come with tips or a plunger as they are meant to be used with a separate machine. I have linked below some cheap stuff that will get you started and come with both wide and fine tips, and the necessary plunger!
Flux Pen
Flux is a literal godsend when you are soldering basically anything! It helps the solder flow onto the connecting metal components. You can use this pen-like marker to easily apply the flux without too much mess. The only thing to watch out for is that you don’t end up with a huge puddle of it on your board, so practice applying it along with your SMD practice.
Desoldering Wick
I used the desoldering wick several times in the video to pull away the excess solder that was causing shorts between the IC leads. This when used correctly can make cleaning up those connections a breeze. Make sure to add some solder to it before trying to remove the excess on the baord, it will give the braid more themal mass and make it easier for more solder to wick into the braid.
But if there is too much the braid will stop accepting solder so make sure you practice this as well. Once there is too much in the braid cut that piece off and start on a fresh section.
Practice Boards
Practice makes perfect, right? This is probably the most important thing to get. There are several variants of this idea that you can get on Amazon or eBay, I have linked one in the picture below from Amazon that I used to gain confidence. It has a good mix of different sized components as well as several package variants to improve your IC soldering skills.
If you would like to build the same board as I have done in the video you can pick one up from RETROCUTION. They make several different variants including prebuilt ones if this is still intimidating.
Tiny USB Hub – 4 Port – DIY Kit
Next Steps
Now all I need to do is keep practicing, I need to assemble the Ambasat 1 board from the Kickstarter campaign because I want to start writing software for it. Look forward to a post on that soon!
UPDATE(08/2021): Amabasat assembly post
Good day! I could have sworn I’ve been to this blog before but after reading through some of the post I realized it’s new to me. Anyhow, I’m definitely delighted I found it and I’ll be bookmarking and checking back often!