High power LED modules use boards that are designed to move large volumes of heat away from the LED as quickly as possible, which also means that soldering connecting wires to the module is going to require more than the typical 25W to 50W soldering iron/station used for standard PCB work.
Instead, you will need to use a temperature-controlled soldering station with a minimum wattage rating of 90W. Higher wattages are even better. This is one that we use for our bench work.
Here are some additional suggestions and recommendations for successful soldering.
- If you ordered several LED modules, we will sometimes ship them 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, you should also separate the module 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.
- Use a small chisel type soldering tip to help focus the heat on the pad. We use ones like these.
- It can sometimes be helpful to add a very small amount of solder flux to the pad using a flux pen like this one.
- Use a small diameter solder. We typically use .020" diameter wire.
- When soldering, be sure that everything is kept impeccably clean.
- We recommend stranded hookup wire not larger than 26 AWG. Be sure that the stripped end is kept very short (not more than about 1.5mm long), and is thoroughly pre-tinned before soldering it to the pre-tinned pad.
- Solder the wire so that 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.