Wettable flank

The use of leadless packages grows rapidly due to increasing component density. QFN/DFN packages have the disadvantage that the solder connection can only be inspected using x-ray processes, rather than Automated Optical Inspection (AOI). For the Automotive industry the AOI option is essential.

Besi introduces together with chemical partner Sytron a complete solution to ensure AOI is possible for QFN/DFN packages.

Processing ensures:

• Immersion Tin plating (autocatalytic process) on full QFN/DFN Cu surface.
• 100% solderability pass after 16hr dry bake.
• 100% solderability pass after 8hr steam aging.
• No exposed Cu areas.

Equipment:

• Handling of Tape Ring with singulated QFN / DFN packages (8” / 10” / 12”).
• 20 Tape Rings per hour.