Solder is an alloy whose main component consists of tin (melting point 232 degrees) and lead (melting point 327 degrees). A solder composed of 63% tin and 37% lead is called a eutectic solder, and the solder has a melting point of 183 degrees. Both tin and lead are conductor materials, and their alloys are of course conductors. In addition, solder has excellent electrical conductivity and is essential for soldering electronic circuits.
Rosin and solder paste are fluxes. Rosin is extracted from the secretions of pine trees. It is non-conductive in the case of dryness and is not corrosive to metal materials such as circuit boards. It is often used as a tin and copper material on circuit boards. Soldering flux for devices.
Solder paste is a synthetic flux that contains certain acidic substances and has a certain corrosive effect on metals. It is also conductive, but because solder paste has better soldering effect than rosin, it is used as a device for iron plating. Tin flux.