This investigation determined the impact of process parameters and materials on the wave soldering process and on solder joint formation. The study provided insight into the process issues encountered with Pb-free wave soldering so that a rational implementation strategy for a robust lead-free process can be achieved.
This project focused on three critical areas:
Fluxes, alloys, components, and board complexity.
Defined "window of opportunity" based on flux amount, preheat temperature, contact time, solder temperature, wave configuration, and atmosphere.
Defined failure levels and defect types using inspection criteria - IPC class 3 combined with best practices, yield determined by hole-fill characterized by 5DX data analysis.
Results from Phase I lay the foundation for Phase II, a broader effort to characterize the reliability of through-hole joints on a test vehicle specifically designed to test the norms and practices used in tin-lead wave soldering and develop new standards for lead-free wave soldering.
: Lead Free Wave Soldering Project Update, Denis Barbini (Vitronics Soltec), October 4, 2007