Introduction: 9 Different Desoldering Techniques
In this instructable, I'll show you 9 different methods for taking electronic components off of circuit boards. Whether you're repairing boards or salvaging parts, it's a necessary skill. This video quickly shows 4 methods.
Step 1: Solder Pot Salvaging and Other Brute Force Methods
This first technique is the most destructive and should only be used when you do not plan on keeping the board. I use this method to salvage a lot of components at once. I have a drawer that I keep scrap PCBs and every once and a while, I'll salvage all the parts from them. I find it very therapeutic and relaxing to remove all the components off of a board.
You can coat the bottom of the PCB with flux to speed things up a bit, but it isn't necessary. After that just use tweezers hold the board over the solder pot and use pliers to remove all the parts you want.
A good alternative to this method is using a small butane or propane torch to heat the bottom of the board up while pulling components off with pliers. Even better if you have a bunsen burner with a mesh screen tripod.
If you're salvaging parts, don't be afraid to use tools to cut the board like a hacksaw or large snips.
Another brute force method is to heat the leads of the part up and smack the board down against an edge of a container. The parts usually will drop in and if not, try adding extra solder. Be sure to wear eye protection because you do not want molten solder in your eye.
All of the desoldering techniques shown in this instructable should be done in a well ventilated room as well as with a respirator if you are going to use a flame to desolder components.
Step 2: Manual Solder Sucker
A good manual solder sucker like this one works pretty well for selectively removing through holes parts from a PCB. Cheaper and smaller units do not work as well. They're marketed as compact but they don't works as well due to the limited stroke length and smaller cylinders.
Step 3: Solder Wick
Solder Wick is basically just copper braid that soaks up solder when you heat it up. Good solder wick should always have flux in it. To use it, simply hole it up the the joint you want to remove solder from and hold a soldering iron up to it. It should soak up the solder fairly quickly. If not, then you probably have poor quality solder wick. If you do, you can doctor it up with some flux like this. Just add flux to the portion of the braid you'll be using before you put it on the joint. You can also add fresh solder to the solder joint beforehand to help a bit if the joint does not have a lot of solder to begin with.
Step 4: Desoldering Machine
If you repair a lot of boards, you absolutely need a machine like this. It is basically a soldering iron with a hole in the center of the tip that is connected to a vacuum pump. Just hold it up to any soldered lead and watch the solder suck right up. I can't recommend them enough.
Step 5: Hot Air Rework Station
For desoldering a lot surface mount components at once, a variable temperature hot air rework station is the best tool you can use. If the board is completed filled with surface mount components, you can just squeegee off all the parts when the board is up to temperature. They use have different tips for different types of components.
You can also use a regular hot air gun but be careful because you can damage other components and the board.
Step 6: Desoldering Tweezers
For selectively removing surface mount components, these heated tweezers are great. Once they get up to temperature you just pluck up the components off the board.
Step 7: Hot Plate
A heavy duty electronic hot plate like this, can be used to heat boards up to soldering temperatures and if you don't have one, I have even seen some people use a pan on their stove to remove components.
Step 8: Compressed Air
For this method, you should definitely make sure to wear eye protection. You use a soldering iron to heat the joint up and then use a can of compressed air to blow the solder off. This is rather messy and I would only recommend doing this on a board that you are salvaging parts from because you can end up with solder where you don't want it. It is rather crude, but it works.
Step 9: The Hard Way
If all you have is a soldering iron and some solder, you can still remove parts, it's just much harder than all the other methods I've shown. Adding fresh solder to the joints is really your friend here. It will really help when trying to desolder components with three or more leads. Sometimes it's hard to heat them all up fast enough but adding flux and a good amount of fresh solder to connect the leads will speed things up. There are low temperate solder wires available like ChipQuik that you can use specifically use to help remove components. In place of solder wire, you can use low temperature solder paste to speed up the desoldering process even more. It is often in an easy to use syringe for quick placement.
A good way of removing surface mount IC components you know are bad is to just snips the leads with a small knife/razor very carefully. Heat up fresh solder and use a solder wick to clean up the area. Do not use snips because you are very likely to damage the pads on the board. Pushing straight down with a razor on the leads as close to the chip body as possible works great.
Step 10: Thank You
Thank you for taking the time to read my instructable. I hope you learned something new. If you feel that I left something out, feel free to leave a comment below. I'd love to hear what your favorite method is.
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I ship out free parts to the first person that messages me after commenting on a new video. These include sensors, components and other small parts. U.S. only because the shipping is always worth way more than the parts.