What is the difference between low temperature tin wire
and usual tin wire? Why use low temperature tin wire, and what advantages does it have over other tin wires?
This has to start from the alloy composition of the low-temperature tin wire. The low-temperature tin wire is a tin wire with Sn and Bi as the main alloy components. The proportion of this tin wire is 42% for Sn and 58% for Bi. The lead-tin wire we usually use is composed of tin-lead alloy, and the lead-free tin wire is basically composed of three metals: tin, silver, and copper. In contrast, bismuth is the focus of low-temperature tin wires.
So why add bismuth metal to low temperature tin wire? Bismuth is added to the tin wire to lower the melting point of the tin wire. The melting point of this tin wire is 138 ℃, and the conventional leaded tin wire and lead-free tin wire are above 180 ℃. For example, the melting point of lead-tin wire is 183℃-245℃, and the melting point of conventional tin-copper-tin wire is 227℃. During our welding process, we will encounter some components that cannot withstand high temperature and need to be welded, but the melting point of leaded and lead-free tin wires is relatively high and cannot be welded, which will cause damage to components that cannot withstand high temperature. Then we can use low temperature tin wire.
Low-temperature tin wires are often used in electronic connectors, LED low-temperature electronics and other industries. The standard wire diameter is 0.5mm-4.6mm, and the tin wire does not contain rosin. It needs to be used together with solder paste or flux. The temperature of the soldering iron needs to be controlled between 190-200°C.