Lead frame

A lead frame (pronounced /lid/ LEED) is a metal structure inside a chip package that carries signals from the die to the outside, used in DIP, QFP and other packages where connections to the chip are made on its edges.

Mechanical connections fix all these parts into a rigid structure, which makes the whole lead frame easy to handle automatically.

The leadframe is made of an alloy the molding compound can adhere to, a thermal expansion coefficient that is as close as possible to that of the die and compound, has good thermal and electrical conductivity, is strong enough and has high formability.

The external leads are then bent to the desired shape.

Advances in lead frame technology have allowed better packing techniques like routable lead frame technology [4] that allow improved thermal and electrical performance.