Safe and Effective Methods for Removing Solder from Electronics Boards
Introduction
Removing solder from electronics boards without damaging the components can be a challenging task, especially when dealing with plated through holes and surface mount devices. This article provides detailed guidance on effective and safe methods for solder removal, complementing existing advice on component removal. Proper techniques can help preserve the integrity of your electronics board.
Removing Solder from Plated Through Holes
Plated through holes can be particularly tricky when trying to remove a component. The residual solder can create an almost impossible barrier, often leading to broken solder joints. Here are some effective strategies:
Option 1: Re-Soldering Technique
To tackle tough solder joints, re-solder the component. Apply heat to the joint with your soldering iron and then use the solder sucker to remove the solder. This process can often break the residual joint and remove all the solder. For stubborn solder, you can re-apply the re-soldering process to further melt and extract the solder. Once the solder has been removed, you can gently pull or lever the component up, melting the remaining solder as you do so.
Option 2: Using a Stainless Steel Tube
For a more direct approach, you may consider using a stainless steel tube. These tubes can be bought in sets or adapted from syringe needles. The tube is inserted between the component pin and the plated through hole. When the solder is molten, the tube is pushed into the hole, solidifies, and is then removed. This allows the pin to be pushed or pulled out when the solder has cooled.
Removing Solder from Surface Mounted Devices (SMD)
Surface mounted devices (SMD) present unique challenges due to the thin layer of solder holding the component in place. Here are some effective methods for dealing with SMD components:
Option 1: Hot Air Tool
The hot air tool, as mentioned in other answers, is highly effective for precise and controlled solder removal. It heats the solder without damaging the component, providing exceptional control and minimal heat exposure. Use this tool to melt the solder around the component and then carefully extract it.
Option 2: Desoldering Hotplate
A desoldering hotplate can also be used, either alone or in combination with the hot air tool. This method is particularly useful for heat-dissipating boards, as it ensures consistent and reliable solder removal without excessive heat impact.
Option 3: Component Removal
If you need to remove a component due to heat-dissipation or for replacement, you have several options. For small components, a soldering iron with a type “K” or knife edged tip can be used to unsolder both ends simultaneously. A thin blade can be slid under the pins of 3 or more leaded devices to ensure they are fully desoldered. Larger components can be lifted off one side at a time, and a short thick piece of solid wire can be used to bridge pins and heat them up all at once. Again, lever up one side of the package at a time to remove the component.
Bulk Component Removal
For bulk component removal or harvesting parts from scrap boards, a heat gun is often the preferred tool. However, using a regular heat gun to melt the solder can result in clumps of parts stuck together, which can be separated after all other parts have been sorted and stored.
You can also use a combination of a heat gun and a heat gun to melt the solder and scrape the parts off with an old knife. For large components, clamping the board in a vise and prying off with a small screwdriver can be effective. To ensure a clean separation, melting the appropriate pin with a soldering iron while the heat gun aids in the process.
Conclusion
Proper techniques for solder removal can save you time and ensure you don’t damage your electronics board. Whether you are dealing with plated through holes or surface mounted devices, these methods provide a reliable solution to your solder removal needs. Experiment with different tools and methods to find what works best for your specific situation.
References
1. Removing Solder from an Electronics Board 2. Seimi Electronics - Desoldering Tools 3. Crystal Fab - Hot Air Tools