A fan-out pattern is a dedicated pattern for a plcc/soic/etc.

A trace (or stringer) runs from the SMT pad to a via.
(Varies on SMT pad size, use thicker trace for caps/res)

The vias are usually on a grid (whatever your typical routing is)
(.013 finished dia. is a good size)

Depening on the density of the IC pattern you may fan-in (under the IC)
as wall as fan-out.

Make sure your vias line up so you can get route between the SMT pads
(if allowed)

For representation only
(not recommended)
O--[] []--O
O--[] []--O
O--[] []--O
O--[] []--O
^   ^    ^
|   |    |___ trace (stringer)
|   |________ SMT pad
|____________ via

Michael Kuczynski       201-393-2122 (Phone)
Allied Signal           201-393-6688 (Fax)
688 Rt46E E/K4
Teterboro NJ 07608
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