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Date: | 26 Jun 1996 18:22:25 -0500 |
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The advantage of not having the thermal relief on the inner layers where
something is not being soldered into the hole is that with surface mount
components and the newer technologies in general the speed of our products
is going up exponetially. Not having a restriction on the inner layer allows
for much better current flow in the substrate and quicker supply of power to
our components. Thermal relief use should be eliminated when ever possible.
Phil Elias
Honeywell Air Transport Systems
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From: [log in to unmask]
To: [log in to unmask]
Subject: DES:,FAB: - Thermal relief for via holes ??
Date: Wednesday, June 26, 1996 7:38AM
Hello TechNet users
I am in need of some input about the necessity of having thermal
relief patterns on inner planes for vias that are being used to
connect surface mount devices to the inner plane.
The design in question is 1.6mm thick, 4-layer, mixed technology
with via size of 0.6mm. The leaded devices that connect directly to the
plane have the IPC recommended thermal relief patterns.
My main question is, are there any major concerns or advantages in
having the vias connecting directly into the plane without relief, I
vaguely recollect concern expressed over reliability of these
connections if extreme thermal cycling is undertaken.
Can anybody help
Regards Gary Willard (Substrate Design Engineer - UK)
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