Learn how to solder components, printed circuits, and connectors easily and reliably.
WARNING: This work refers to electrical soldering only.
Learning the correct technique ensures trouble-free, reliable electrical solder joints that last, and allows you to easily and cheaply repair electrical equipment when simple circuit joint faults occur.
- Make sure it's clean. Printed Circuit Boards (PCBs) may need washing—use a mild soap or detergent, rinse thoroughly, blot with a paper towel, and allow the PCB to dry completely.
- Clean component leads by lightly scraping with a blade, or use emery or wet-and-dry paper (used dry). Flux helps clean the joint and may be beneficial if applied sparingly to a reworked joint.
- Ensure the joint is mechanically stable. Solder is not truly a glue; it provides electrical continuity for reliable circuitry. If components move during soldering, the joint may be unreliable or fail completely.
- Use a suitably sized soldering iron with a clean bit. Using too small a bit for larger solder joints is inefficient and may heat the joint unevenly. This can cause the solder to set in different strata or layers, resulting in an electrically poor connection known as a "dry joint." Conversely, using too large a bit is unwieldy and may overheat components, causing them to fail completely.
- Check the tip temperature. You can do this by touching the tip with the end of the solder, which should melt immediately to form a thin film, tinning the end of the tip. This helps conduct heat to the work evenly. If the tip is not up to working temperature, leave it a little longer to heat up.
- Heat the joint—component leads and PCB pads—for a brief time (<5 seconds).
- Apply solder to the joint—ideally from the side opposite the iron tip. Once the joint reaches working temperature, the solder will melt and flow.
- Remove the solder and then the iron. If you remove the iron first, the solder may stick to the work; simply reapply the iron and allow the solder to melt off the work.
- Feeding just the right amount of solder at the right temperature is a skill you will soon learn. If you apply too much, the excess can be removed using a desoldering pump or braid.
The same principles apply to plumbing solder joints for water pipes, though modern push-fit and compression fittings may prove easier to use for a one-off repair.
A good solder joint will be smooth and shiny, with ideally a "volcano" shape—technically, a concave meniscus.
How to Make a Good Solder Joint
Learn how to solder components, printed circuits, and connectors easily and reliably.
WARNING: This work refers to electrical soldering only.
Learning the correct technique ensures trouble-free, reliable electrical solder joints that last, and allows you to easily and cheaply repair electrical equipment when simple circuit joint faults occur.
- Make sure it's clean. Printed Circuit Boards (PCBs) may need washing—use a mild soap or detergent, rinse thoroughly, blot with a paper towel, and allow the PCB to dry completely.
- Clean component leads by lightly scraping with a blade, or use emery or wet-and-dry paper (used dry). Flux helps clean the joint and may be beneficial if applied sparingly to a reworked joint.
- Ensure the joint is mechanically stable. Solder is not truly a glue; it provides electrical continuity for reliable circuitry. If components move during soldering, the joint may be unreliable or fail completely.
- Use a suitably sized soldering iron with a clean bit. Using too small a bit for larger solder joints is inefficient and may heat the joint unevenly. This can cause the solder to set in different strata or layers, resulting in an electrically poor connection known as a "dry joint." Conversely, using too large a bit is unwieldy and may overheat components, causing them to fail completely.
- Check the tip temperature. You can do this by touching the tip with the end of the solder, which should melt immediately to form a thin film, tinning the end of the tip. This helps conduct heat to the work evenly. If the tip is not up to working temperature, leave it a little longer to heat up.
- Heat the joint—component leads and PCB pads—for a brief time (<5 seconds).
- Apply solder to the joint—ideally from the side opposite the iron tip. Once the joint reaches working temperature, the solder will melt and flow.
- Remove the solder and then the iron. If you remove the iron first, the solder may stick to the work; simply reapply the iron and allow the solder to melt off the work.
- Feeding just the right amount of solder at the right temperature is a skill you will soon learn. If you apply too much, the excess can be removed using a desoldering pump or braid.
The same principles apply to plumbing solder joints for water pipes, though modern push-fit and compression fittings may prove easier to use for a one-off repair.
A good solder joint will be smooth and shiny, with ideally a "volcano" shape—technically, a concave meniscus.
How to Make a Good Solder Joint
By Howtodotips
Learn how to solder components, printed circuits, and connectors easily and reliably.