What is the melting point of solder?

The Melting point of solder is the temperature at which the solder changes its state from solid to liquid. The typical melting point of the general solder is in the range of 90 to 450 °C (190 to 840 °F | 360 to 720 K).

Solder is an easily fusible adhesive metallic material melts when heated and solidifies on cooling. It is used in the electronics field to connect component leads to the pads on a PCB. It joins the two metals electrically and mechanically after cooling.

Solder is available in a wide range of alloy compositions. The % weight of alloy compositions decides the melting temperature of the solder. Here, some lead-free solder composition and their melting temperatures are given.

Solder can be classified as lead-based solder (made of a composition of lead and tin) and lead-free solder (made of a composition of other metals, such as tin with silver, except lead). Another type of solder is the eutectic solder.  The eutectic solder is an alloy that melts and freezes at one single temperature. For example, 95.6Sn3.5Ag0.9Cu melts and freezes at 217°C.

The solder used in electronics soldering is known as soft solder.

The use of lead-based solder is harmful to human health and the environment. Hence, the use of lead-based solder is prohibited by the RoHS directive (2002/95/EC) became effective on July 1, 2006. Hence, mostly, lead-free solders are used in electronics soldering.