scope:

EXECUTIVE SUMMARY

Four immersion silver plated boards were submitted to the lab for evaluation. The boards were supplied from three different vendors with different silver thicknesses.

• Vendor A 3X SAC
• Vendor G X SAC
• Vendor D 3X Lead
• Vendor G X Lead

Five Pb-Free components were assembled on the boards using Sn-Pb and Pb-Free pastes. More voiding as well as Champagne voiding was seen in A3X SAC and GX SAC boards.

The intermetallic layers at the component and board sides were found to be properly formed on all boards.

There was no significant difference in microstructure formed on D3X Lead and GX Lead boards.

There were more Ag3Sn plates and they were larger in A3XSAC than GX SAC boards.

It was observed that the Pb-free balls of the BGA components were not completely mixed with the Sn-Pb paste on boards D3X Lead and GX Lead.