Wire bonding is the part of the fabrication that allows an electrical component to communicate with the outside world. A thin electrically conductive wire – typically gold, aluminium, copper or silver – is used to allow electricity to flow from contacts on the component to, or from, its packaging. There are two commonly used types of wire bonding – wedge and ball. Which one is more suitable depends on the substrate, the contact material, the bonding material, and a number of other physical factors. Bonders can be manual or automated, and some can feature pattern recognition software to help speed the bonding process up.