Leadframe alloys Cu-Fe-P and Cu-Cr as an alternative to Cu-Zr for wheel-speed magnetic sensor package

Investigations of alternative Cu-based alloys were carried out as an opportunity for improvement on the quality, reliability and cost reduction. CuFeP and CuCr were successfully evaluated as an alternative leadframe alloys to the existing CuZr alloy on a wheel-speed magnetic sensor package through thermo-mechanical simulation, assembly and test performance, and reliability tests performance. Material properties and themo-mechanical simulation of the leadframe alloys showed that the CuFeP and CuCr alternative alloys have higher resistance to elastic and plastic deformations than the existing CuZr alloy. The assembly, final test, and reliability tests performances of the samples built using CuFeP and CuCr alternative alloys proved that the ferromagnetic impurities did not affect the functionality of wheel-speed magnetic sensor device inside the package. Furthermore, the leadframe-to-mold adhesion performance of the CuFeP and CuCr alternative alloys also showed outstanding result as compared to the existing CuZr alloy.