High-power LED modules are designed to move large volumes of heat away from the LED as quickly as possible, making soldering connecting wires to the module using a standard 40 W or 60 W soldering iron somewhat challenging. It is possible, but it will require some practice and patience.
The better option is to use a temperature-controlled soldering station with a wattage rating of 95 W or higher. Wattages in the range of 120 W to 150 W work best. Here are a couple of soldering station suggestions:
Some additional tips and recommendations for soldering connecting wires to high-power LED modules.
- If you order several LED modules, they will sometimes be shipped as a v-scored, connected array . Always separate the modules from the array before you try to solder them. If the module comes with a carrier tab, separate it from the carrier tab, as the extra mass will make it much harder to solder.
- Solder the wire connections to the module before you fasten the module to the heatsink.
- Place the module on a thermally non-conductive surface while you are soldering. Don’t solder the module on an ESD mat! It will get hot enough to melt the mat.
- Use a small chisel-type soldering tip to help focus the heat on the pad. We use ones like these.
- When soldering, be sure that everything is kept impeccably clean.
- Adding a very small amount of solder flux to the pad can sometimes be helpful.
- Use a small-diameter solder. We typically use .020″ solder wire.
- Use the smallest possible gauge of hookup wire, not larger than 26 AWG. Ensure the stripped end is kept very short (about 1.5mm long) and is thoroughly pre-tinned before soldering it to the pad.
- Ensure that you bring the base (not just the solder pad) up to temperature before creating a solder puddle on the pad. Your initial preheat and dwell time will be longer than you are used to.
- Have your wire prepped, tinned, and ready to attach once you have a molten puddle on the pad.
- Attach the wire so it is perpendicular to the pad rather than lying flat and coming out parallel to the board. This helps to ensure that the connection does not touch the edge of the LED module.
- On smaller modules, it can sometimes be difficult to keep the module in place as it will tend to want to stick to the tip of the iron. To help hold the base down, use the tip of a small flat-bladed screwdriver with a third-hand holder.
- Attaching the second wire to smaller modules can weaken the first wire connection as the heat quickly travels across the base to the other side. The same flat-bladed screwdriver can help prevent this by acting as a thermal block.