The lead frame is a thin metal plate part to be used in semiconductor packages such as IC, LSI, etc.

As the chip carrier of the integrated circuit, the lead frame is a key structural component that realizes the electrical connection between the lead end of the internal circuit of the chip and the outer lead by means of bonding materials and forms an electrical circuit.

The function of the lead frame requires the lead frame material to meet the following properties:

① Good thermal conductivity and electrical conductivity, which can reduce the adverse effects caused by capacitance and inductance, and is also conducive to heat dissipation;

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

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

④ Good flatness and small residual stress;

⑤ Easy to punch and process without burrs;

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