Hacking the Xbox

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Hacking the Xbox: An Introduction to Reverse Engineering
Leave Space for Via Fanouts on Surface
Mount Devices
Surface mount devices offer a great density advantage when compared
with the older through-hole componentry that used to be the de facto
standard. However, surface mount components still require throughhole
vias for routability, especially in complex and/or auto-routed
designs. These routing vias are referred to as “fan-out” vias for SMD
pads. Figures C-2 and C-3 demonstrate the use of fan-out vias on a
surface mount part.
Decoupling Capacitors Fit Nicely Under
SMD Pads
The most common passive component in a typical digital design is the
decoupling capacitor. These tiny capacitors are everywhere, and they can
consume valuable routing and via fan-out space if they are not properly
placed. If you are willing to create a double-sided surface-mount board,
decoupling capacitors can be placed on the board side opposite the target
component’s pads. By placing these components under the component’s
pad space, you are not consuming any via fan-out area. In fact, a well-placed
Figure C-2: Four views of a circuit board layout. From the top left, clockwise:
fabricated circuit board with components; top-layer circuit board view in PCB
layout program; all-layers circuit board view in PCB layout program; top and
bottom only layers view demonstrating two-sided SMT layout.