Our favorite tools have a new home on the wiki. Each week we’ll muse about one of them. Have your own tool review? We’ll post that too!
This week’s tool is a collection of stuff: the things we use for soldering. We regularly work with surface mount (SMD) parts down to 0603, but it doesn’t take expensive or exotic tools:
- Solder. We use 60/40 tin/lead solder, it is the only way to go for hand prototyping. It makes recycling parts with hot-air much easier than lead-free solders, which is probably a net positive for the environment. Most solder has some flux, ours lists 2%, but it is never enough, use more! We had been using a 0.7mm wide solder, but recently found a 0.5mm reel. The 0.5mm solder is thin enough to solder SSOP and QFP pins individually, which means there’s less excess solder that needs to be mopped up with wick.
- Flux. Flux helps solder flow better, and keeps it out of places you don’t want it. Don’t even try to solder without copious amounts of this magic goo. Our syringe of flux came from a surplus store. According to the label it expired in 1991, but it still works great!
- Solder wick. There are almost always solder bridges between the tiny pins on hand-soldered SMD chips. Apply a little extra flux to the pins and mop up the excess solder with wick. Wick is the trick to soldering SMD without attending to each pin individually – glob down a bunch of solder and soak up the excess with wick, enough remains behind to connect the part to the PCB.
- A sponge. An iron covered with soldering gunk doesn’t conduct heat well. A clean iron is much easier and faster to work with. We use a giant natural fiber sponge moistened with a bit of water to clean the iron. We give it a quick swipe whenever the iron looks dirty. Go for a big one, the tiny sponge in the iron holder is totally insufficient.
- Tweezers. We use ’00’ size surgical tweezers to hold SMD parts while soldering. The pointier the better. These were 50 cents at a surplus store.
- Jewelers loupe. A loupe magnifier is a must for inspecting SMD connections. It doesn’t need to be expensive. We won this loupe in Hacked Gadget’s Halloween contest a few years ago.
- Sticky tack/poster tack/Blu-Tack. This is a sticky putty often used to hang posters in student dorms. We use it like many people use a helping hand. It can hold a board steady and keep parts in place. We also put it on the end of a pencil for a simple vacuum-lifter alternative. Also used heavily in the photo studio.
- A bright desk lamp. The importance of a bright light cannot be understated, especially for surface mount soldering. The smaller it is, the harder is is to see in the dark.
- Soldering stations and Storage are within reach.
Board stuffing is an art. Nobody does it the same. What’s in your prototype building arsenal?
There’s more tools too.