Process Differences between SnPb and Pb-free

There are changes to ON Semiconductor’s internal manufacturing processes and to our customers’ board assembly processes by converting to Pb-free. The impact of Pb-free to ON Semiconductor is in our plating processes. We have changed our plating material to matte Sn (tin) from SnPb. All ON Semiconductor assembly lines for Pb-free products utilize MSA based plating baths.

Our customers' reflow processes are impacted by the conversion to Pb-free. The temperatures for Pb-free reflow are substantially higher than the current reflow temperatures. We qualify our Pb-free parts at 260°C to prove reliability at the higher temperatures.

Plating Thickness

The thickness spec for matte tin plating is 7.5µ minimum; 10 um nominal.

Process Controls

ON Semiconductor factories have implemented strict process control procedures in their plating operations. Some of the parameters that are monitored regularly include carbon content, concentration of impurities, and current density.