Semiconductor lead frame

The lead frame is a thin metal frame used to connect the contact points of the internal chip of the semiconductor integrated block and the external wires. It is a major structural material for semiconductor packaging and accounts for 15 % of the semiconductor packaging material market.

What is Lead Frame

The lead frame is mainly composed of two parts : die paddle and lead finger. As the chip carrier of integrated circuits, the lead frame is a key structural component that forms an electrical circuit by means of bonding materials ( gold wire, aluminum wire, copper wire ) to make the internal circuit extraction end ( bonding point ) of the chip through the electrical connection between the internal lead and the external lead, which plays a bridge role in connecting with the external lead.

In integrated circuits, the lead frame and packaging materials play the role of fixing the chip, protecting the internal components, transmitting electrical signals and emitting component heat outwards.

The lead frame material should meet the following characteristics : 

1 good thermal conductivity, can reduce the adverse effects caused by capacitance and inductance, but also conducive to heat dissipation ; 

2 low thermal expansion coefficient, good matching, brazing, corrosion resistance, thermal resistance and oxidation resistance, good electroplating ; 

3 Sufficient strength, stiffness and formability. Generally, the tensile strength is greater than 450 MPa, and the elongation is greater than 4 %. 

4 good flatness, small residual stress ; 

5 easy blanking processing, and not burr ; 

6. Low cost, can meet the requirements of large-scale commercial applications.