What indicates a properly formed solder joint?

A properly formed solder joint is characterized by a smooth, shiny finish and the appropriate height. This shiny appearance indicates that the solder has flowed well and formed a strong bond between the components and the circuit board, which is essential for reliability and electrical conductivity.

When the solder joint is smooth and shiny, it shows that the solder has melted properly and cooled in the proper way, which is a sign of good soldering technique. The appropriate height of the solder joint is also important, as it ensures that the joint has enough material to provide a strong connection without being excessive, which could lead to bridging or other issues.

Other characteristics, such as rough and dull appearances, typically signal poor soldering practices, which can lead to weak joints or reliability issues over time. Additionally, the use of an excessive amount of solder or the presence of multiple colors on the solder surface can indicate contamination, improper heating, or insufficient soldering techniques, all of which detract from the integrity of the joint.