Solder wire, solder bar, and solder paste can be divided into hard solder and soft solder according to their melting points; they can be divided into tin-lead solder, lead-free solder, silver solder, copper solder, etc. according to their composition. The shape of commonly used solder: solder is often processed and formed according to the specified size when used, and there are many types such as sheets, blocks, rods, strips, and wires.

(1) Wire solder - usually called solder wire, with rosin flux wrapped in the center, called rosin core solder wire, commonly used in manual soldering.
(2) Sheet solder - commonly used for soldering silicon wafers and other sheet solder parts.
(3) Strip solder - commonly used in automatic assembly production lines, using automatic welding machines to punch out a section of the strip solder for welding to improve production efficiency.
(4) Solder paste - made by mixing solder and flux powder together. When welding, first apply the solder paste on the printed circuit board and then solder. It has been widely used in automatic patch processing.

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