What are wettable flanks? Is there any difference between packages with wettable flanks and other leadless packages?
Can we say the package given above has wettable flanks?
\$\begingroup\$
\$\endgroup\$
Add a comment
|
1 Answer
\$\begingroup\$
\$\endgroup\$
The side metal has been plated. See for example:
https://www.besi.com/fileadmin/data/Fotos_diversen/wettable_flanks/Meco_Wettable_Flank_White_Paper_A.pdf
This seems to be a little white paper, from the manufacturing side. The package starts out as a larger plate, the sides are cut off exposing bare copper, then the whole thing is tin-plated to produce wettable flanks.
The package can also be plated before cutting, but only the bottom face is exposed before cutting. That leaves bare copper sides, that are unlikely to wet during reflow.
The wetting is important for inspecting solder joints: the toe fillet can be confirmed visually with AOI (automated optical inspection). In contrast, non-wettable lands are basically LGA type joints, and must be x-rayed.
answered Sep 13, 2022 at 11:18