Afri Singh wrote:-
>Can anyone shed some light on a problem i am having in my lam dept.
>We are getting pockets of air (bubbles) trapped in low pressure areas
>towards the middle of the panel
>Seen only on the top or bottom panel of each book
>This only happens on cores with 2-3 oz cu.

Afri

If you are pressing with a vacuum press, you should not have a problem.
The full vacuum needs to be applied before closing up the press. If
there is no pressure on the stack, then this need only be for a few
minutes. If you are hot starting this is difficult, so you could use a
cold start for these problem boards. Once the panels are under pressure,
the air will not be able to escape and will cause delamination when the
hot press pressure is released.

Regards
Paul Gould
Teknacron Circuits Ltd
[log in to unmask]
Isle of Wight,UK

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