For lead-free welding of products exported to Europe, America and other countries, the tools and components used must be lead-free.
Lead-free solder bars have light yellow traces, because lead-free generally contains copper metal. Lead-free solder bars are basically lead-free (the EU ROHS standard is less than 1000PPM, and the Japanese standard is less than 500PPM). Lead-free solder bars generally contain tin, silver or copper metal elements.
Intuitive method of soldering iron temperature during lead-free solder bar soldering:
Judging by the color of the solder: Dissolve a small amount of tin wire containing rosin on the tip of the heated soldering iron, and then wipe it off on a wet sponge. After 2 to 3 seconds, observe the discoloration of the tin coating on the tip. Determine its temperature.
The silvery white temperature is normal.
Golden yellow and golden yellow with blue stripes have a high temperature.
Purple and dark gray are super hot.
Use welding smoke to judge:
The temperature of the tip of the soldering iron is determined by the amount of fume from the flux.
When the temperature is low, the smoke produced is rare and takes a long time.
The dense smoke generated at high temperature rises rapidly and disappears in a relatively short period of time.
At normal temperature, the generated smoke disappears in about 8 seconds.
Lead-free solder bar is pale yellow and has an alloy melting point lower than that of any of the single metals that make up the alloy. Lead-free tin has a high melting point. The melting point of lead-tin alloys varies depending on the composition ratio.