QFN exposed pad

[dsicon]

on the 16F684-I/ML
the QFN pkg dwg shows an exposed pad on the bottom like a heat pad
but i don't where it explicitly says whether this is connected to anything internally and whether or not it should be grounded
anybody know ?

[dhouston]

From http://www.intersil.com/data/tb/TB389.pdf by Intersil titled PCB Land Pattern Design and Surface Mount Guidelines for QFN Packages

The PCB “thermal land” design for the exposed die pad
should include thermal vias that drop down and connect to
buried metal plane(s). This combination of vias for vertical
heat escape and buried planes for heat spreading allows the
QFN to achieve its full thermal potential.

[Melanie]

Yeah... Figure 19... let's see you solder the row of connections behind the big cap with that little iron of yours...

[dsicon]

right, but the question was for the PIC what electrical net to tie it to if any

re fig 19 we often have to pull out parts to do such rework