Frequently Asked Questions About Lead-Free Hand Soldering (Part 3 of 4)
QUESTION: What changes are necessary in soldering tool design/performance when working with lead-free solder?
ANSWER: Soldering irons and stations will require the capacity to bring the joint to sufficient temperature rapidly and hold that temperature with minimal recovery time. More powerful tools will do the job better just like a car engine with more horsepower will pass quicker and climb hills easier.
Besides having the necessary power, the optimal soldering tool will also possess very efficient heat transfer to the work. This efficient heat transfer, plus sufficient power, will ensure that recovery rates are very fast and will not slow down operations when moving from joint to joint. In addition dwell time on the PCB will be minimized.
Efficient delivery of the heat to the joint depends on a number of factors:
- Adequate power from the heater
- Proximity of the heater to the working end of the tool
- Thermal efficiency in delivery of the heat to the joint (geometry and tip/heater materials)
- Some means of quickly sensing the need for delivery of more heat (location of sensor)
- Accurate control of the tools temperature (microprocessor control with no overshoot).
