It depends on what stack up is used.  1 over 2 probably is not stocked.  A 4
layer made with a center core of 2 ounce both sides and foil or cap layers
is not a nonstandard layup.  Many computer cards used to be made that way
and spot faced off to see alignment targets inside for drill registration.
Something in a six layer where you do not put the heavier foil on either
side of a layer makes it get interesting and might cause heart burn.
----- Original Message -----
Wrom: OYIYZUNNYCGPKYLEJGDGVCJVTLBXFGGMEPYOQ
To: <[log in to unmask]>
Sent: Monday, March 18, 2002 5:11 AM
Subject: [TN] Non-Standard material


> Good Morning Technetters...
>
> I need your input / advice. Our manufacturing facility has recently
(within
> a year or so...) switched to a new PCB fabricator. I'm now starting to get
> complaints from manufacturing that our fabricator is having trouble
> obtaining the 'non-standard' material that we are specifying.  First of
all,
> I don't believe that I'm specifying non-standard material, this is where I
> need your input. Most of our boards are multi-layer, usually 4 to 6 layers
> and we use FR4. We typically specify 2-oz copper on the internal power and
> ground layers and sometimes 1-oz copper for the outer signal layers. Is
this
> non-standard? The fabricator says that they typically don't stock 1 over 2
> copper. Maybe I'm missing something but I thought that the stackup could
be
> made of individual copper sheets of various copper weights as long as the
> layer sequence was balanced.
>
> All comments welcome...
>
> Lou
>
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