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>Pete Waddell wrote:
>>
>> change vendors
>>
>> Subject: Inner layer PAD Suppression or NOT?
>>
>> I am currently debating the pro's & con's of suppressing
>> non-functional inner layer pads and have found our PCB
>> fabricators have differing views on which is best.
>I have been told two advantages:
> + increasing the life of drill bits,
> + less chance of clearance problems (shorts).
>.....
>Anyway, just recently I have heard that plated holes are
>stronger with the extra pads.
>OK, what's the scoop, guys?
>Jack
Leave em in __ More chances to short but less prone to z-axis
problems such as lifted pads or even cracking copper in small
holes.
Take em out __ A lot less chance for shorts in high density work
but more z axis expansion. You might get a flatter board
too.
I suggest looking at the design and its potential troubles and
decide based on the board. A good middle road is to leave em in
the inner layers closest to the outside of the board ( the
part that gets hot) and take the rest out. I've seen this work
very well on a 14 layer.
Most board shops have preferred methods. I'd be inclined to ask
them to review the design.
[log in to unmask]
Hallmark Circuits Inc.
San Diego, Ca.
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