4 Best Uses for Solder Paste

Solder paste is solder that comes in a tube, mixed with flux. Flux is a material that helps clean the soldered area during the process. The most common for this use is "no-clean" flux, which as it says, doesn't need to be cleaned off when you are finished. Solder paste is applied from the tube and the whole assembly is heated. The solder melts and "reflows" into place. It is used in electronics manufacturing and also by hobbyists. Manufacturers have special ovens for the process, but it can be done with a hot plate or toaster oven. (These items should not be used to cook food after soldering in them! Solder of all kinds often contain lead.) Solder paste usually needs to be refrigerated. It will be only be shipped overnight. Order it only when you will be using it soon.

Four of the best uses for solder paste are:

1. Screen Printing onto Circuit Boards

This is often done by manufacturers making large numbers of printed circuit boards, and they want it to be as precise as possible. A stencil is placed over the board. Solder paste is applied over the whole stencil and then the whole thing is heated. The solder reflows into the places where it is needed.

2. Electronics Hobbies

Whether you build your own radios, computers, robots, or any other electronic devices, you have to solder circuit boards together. Instead of using a hot soldering iron and doing one solder at a time, you can apply solder paste, then heat the whole board. All the little beads of paste will reflow neatly into place. Let it cool gently and your board will be done.

3. Very Small Things

Some chips are so small that attempting to use a traditional soldering iron would be useless. With solder paste, you can apply a little, or even mask off the right area with tape. Heat the chip until the solder melts, let it cool, and remove the tape.

4. Working Quickly and Accurately

Using solder paste can be a lot faster than using a soldering iron. It takes some practice to get the paste where you want it, but once you are used to it you can work fast and then place the board in the oven for heating. The tip of a tube or even a syringe can place the paste where it is needed, even in hard to reach places.

Solder paste can be cleaned off and redone if necessary. Wash your hands after you handle it, it often contains lead. Lead free solder is becoming more available as countries around the world ban the use of lead. If you use a toaster oven, there are devices available that will allow you to control the temperature and timing accurately. Don't move your circuit board until it has cooled enough that all the pieces stay in place.