[SI-LIST] : Board Stack-up

Peterson, James F (jfpeterson@space.honeywell.com)
Tue, 21 Oct 1997 08:37:36 -0400

SI Wizards,
If you have the time, take a look at this stack-up and give me your
opinion. This stack-up shows a 13 layer board, but actually it's 26,
with the other 13 being a mirrored reflection. It will be in a
relatively harsh climate, thus the thermal layer (which is copper, but
connected to chassis ground instead of circuit ground). You'll notice
that I'm straying from the dual stripline approach on layers 6 & 7 and
also on 2 & 12. Layers 6 & 7 are suppose to give me very effective
capacitor at high freq's. Layers 2 & 12 would normally, for us, be
ground layers, but with the new config. at 6 & 7, I wouldn't have
enough signal layers. (2 and 12 still have an adjacent ground plane for
return currents.)

1 -- Pads/Breakouts only
2 -- Sig1
3 -- Gnd
4 -- Sig2
5 -- Sig3
6 -- Vcc
7 -- Gnd
8 -- Sig4
9 -- Thermal (a copper plane, but tied to chassis gnd, not circuit
gnd)
10 -- Sig5
11 -- Gnd
12 -- Sig6
13 -- Pads only

Thanks in advance for your time and input,
Jim
Jim Peterson
jfpeterson@space.honeywell.com
Honeywell, Space Systems Division, M/S 934-5
13350 US 19 N., Clearwater, FL, 34624
813-539-2719