What is Gull Wing Lead

What is Gull Wing Lead

A gull wing lead is a type of terminal lead form used in the PCB industry. It refers to a surface mounted device lead that flares outward from the device body, resembling the shape of a seagull’s wings. This lead configuration is commonly found in surface mount devices (SMDs) such as TSSOP (Thin Shrink Small Outline Package) and TQFP (Thin Quad Flat Package).

Gull wing leads are crucial for connecting the component and the PCB. They are known for their reliability, especially in fine-pitch, high pin-count packages. The shape of the leads allows them to be properly oriented to the land pattern, with each lead centered across the width of the land. The leads are planar, and the fillets are shiny and concave. The heel fillet, which is the fillet at the base of the lead, is also evident.

To ensure optimal solder joint formation and reliability, following the recommended design guidelines provided in the component’s datasheet is important. These guidelines may include information on the preferred planarity or coplanarity of the lead to the land pattern area, the width of the end joint, the presence of a heel fillet, and the lateral/side overhang of the component lead.