How to choose a soldering iron (lead-free soldering station for components) in factories

Lead-free soldering is now common, and factories cannot purchase electric soldering irons (soldering stations) based on traditional concepts. Although ordinary temperature-controlled electric soldering irons on the market can be set to 400 degrees or higher, in fact, their heat capacity and temperature recovery capabilities are often insufficient to handle lead-free high-temperature soldering in the case of colder solder joints. During soldering, the heat consumption capacity of lead-free tin wire, which has a melting point about 34°C higher than that of lead-free tin wire, is relatively large. If an ordinary temperature-controlled soldering station is used for soldering without increasing the temperature (especially when the solder joint area is large), insufficient heat energy replenishment will often cause burrs on the tin joints, cold solder joints, and slow soldering speeds. Therefore, in order to achieve the appropriate welding effect, the soldering temperature of the soldering iron must be increased accordingly, but increasing the welding setting temperature will also bring many negative effects.

A. Lead-free tin wire is more susceptible to oxidation than lead solder wire, and high temperature acts as a catalyst. The oxidation rate increases exponentially with the increase of temperature. Therefore, welding at extremely high temperatures is very likely to cause mechanical contact type cold soldering (the solder does not form a molten alloy layer between the workpieces being welded) and grayish white solder joints that are not bright.

B. An ideal soldering iron does not need to be idle at a high temperature, eliminating energy storage, and instantly applying the energy obtained from the power supply directly to the welding point. This can both minimize energy loss and achieve good welding. However, ordinary soldering irons cannot achieve this due to their slow heating speed. They can only store enough heat energy to reach the temperature required for the welding load by increasing the idle temperature. However, higher temperatures will have a great thermal shock on delicate components, directly or indirectly affecting the circuit performance and the performance of the entire machine.

C. Generally, electronic factories, especially optoelectronic product factories, have strict control over the setting of welding temperature. The lower the temperature setting, the better, provided that the welding conditions can be met. Therefore, a higher welding temperature cannot meet the welding process requirements set by the factory.

When purchasing a lead-free soldering station (soldering iron), you must first ensure two points:

1. Ensure the welding temperature is around 350℃

2. Ensure welding speed of 3-4 seconds per welding point

      Only those that can guarantee the above two points can be called lead-free soldering stations. It is not advisable to increase the soldering temperature in order to ensure the soldering speed, as this will affect the quality of the solder joints and shorten the service life of the soldering iron tip.

    Lead-free soldering stations (soldering irons) generally have several powers of 80W, 100W, 120W, and 150W. For most solder joints, an 80W lead-free soldering station (soldering iron) can meet the needs. If the solder joint is too large, you can choose a lead-free soldering station (soldering iron) with a higher power.

      In short, when purchasing a lead-free soldering station (soldering iron), you must ensure the above two points. A lead-free soldering station (soldering iron) that cannot meet the above two points cannot be called a true lead-free soldering station (soldering iron).