Bonding wires

Bonding wires are fine, high-purity metallic wires (typically gold, aluminum, or copper) that establish electrical interconnections between the bond pads on a semiconductor die (such as an LED chip) and the corresponding terminals on its package substrate or lead frame. In LED arrays, these wires transmit electrical current to individual LED chips, enabling their illumination. The bonding process involves thermosonic or ultrasonic techniques to create metallurgical bonds at both ends of the wire.

Bonding wires function as conductive pathways by utilizing thermosonic or ultrasonic bonding. A capillary tool feeds the wire, and heat (thermosonic) or ultrasonic energy is applied to the wire tip, creating a metallurgical bond (ball bond or wedge bond) at the chip's bond pad. The wire is then looped to the package terminal, where a second bond is formed. This creates a low-resistance electrical connection that allows current to flow from the package to the semiconductor die.