How To Pick Your Soldering Iron Temperature

Summary

There is no single correct soldering-iron temperature for microsoldering. The right setting depends on the solder, the board and connection, the iron tip, and the operator’s experience. The goal is to transfer enough heat to complete the job efficiently without damaging components or the board.

Factors that affect the temperature you need

• Solder type: Factory boards usually use lead-free solder, which melts at roughly 217–227°C. The presenter’s 63/37 leaded solder melts at 183°C. In practice, the iron must be set higher than the solder’s melting point because the board draws heat away from the joint.
• Board features: Ground planes, voltage rails, wide traces, and large or thick PCBs dissipate or absorb heat, making joints harder to bring to melting temperature. Smaller, thinner boards generally need less heat.
• Part size: Large components and metal shields can carry heat away from a joint.
• Tip size and contact: A larger tip transfers more heat because it has more contact area. Using the side or edge of a tip can also improve contact compared with touching the joint with only the tip’s very end.
• Tool capability: A powered soldering station replenishes heat more effectively than a lower-wattage portable iron, especially when working on thick boards or large ground connections.

Thermal-camera demonstrations show heat spreading through traces and planes. They also illustrate why a setting that works on a small board may struggle on a large, thick board, even when the iron temperature is unchanged.

Practical temperature guidance

• Treat 350°C as a reasonable starting point for many tasks, particularly when learning.
• The presenter commonly uses 375–425°C, adjusting for the board, joint, solder, and component. Small boards or heat-sensitive parts may call for a lower setting, while demanding connections may need a higher one.
• Beginners are advised to start around 350°C and avoid leaving the iron on the board for too long.
• With experience, working quickly at a higher temperature can be preferable to applying lower heat for an extended time, which can thermally stress the board.
• Adjust the temperature in practical increments, such as 25°C at a time, rather than searching for an exact setting.
• Use flux when soldering. The presenter leaves it out of the demonstrations to make heat movement easier to see.
• Experiment on boards or parts you can afford to damage, especially when getting used to a new tool. Different irons can behave differently at the same displayed temperature.

Preheating and special cases

BGA rework is an exception to the general advice: sensitive chips and larger heated areas require careful control of both temperature and exposure time.

For large, stubborn connections—such as clearing the ground holes of a large port—the presenter recommends preheating the board with hot air. His starting point is about 250°C at roughly 50% airflow, with the nozzle kept moving. Preheating reduces how much heat the iron must supply to the joint.

Hot air is treated as a separate topic because it heats a larger area for longer and also requires careful choices about temperature and exposure. Portable irons can be useful on small boards and joints, but may struggle with large ground planes and thick boards. A soldering station, or hot air to assist with preheating, is more suitable for those jobs.

The central lesson is to understand how heat moves through the particular board and joint, then choose a workable starting temperature and adjust in sensible increments—not to chase one universally “correct” number.

Speakers and sources featured

• The presenter/narrator — the sole speaking source in the subtitles. He explains the guidance and demonstrates it using soldering irons, circuit boards, and a thermal camera.