EN5337QI
Design Considerations
several small pads being exposed on the
bottom of the package.
Exposed Metal on Bottom of Package
Lead frames offers many advantages in
thermal performance, in reduced electrical lead
resistance, and in overall foot print. However,
they do require some special considerations.
Only the large thermal pad and the perimeter
pads are to be mechanically or electrically
connected to the PC board. The PCB top layer
under the EN5337QI should be clear of any
metal except for the large thermal pad and the
perimeter pads. The “grayed-out” area in
Figure 6 represents the area that should be
clear of any metal (traces, vias, or planes), on
the top layer of the PCB.
In the assembly process lead frame
construction requires that, for mechanical
support, some of the lead-frame cantilevers be
exposed at the point where wire-bond or
internal passives are attached. This results in
Figure 6: Lead-Frame Exposed Metal (package bottom view). Grey area highlights exposed metal
below which there should not be any metal (traces, vias, or planes) on the top layer of PCB.
Recommended PCB Footprint
Figure 7: EN5337QI Package PCB Footprint
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6/18/2009
Rev:D
ENPIRION [ ENPIRION, INC. ]
