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May 2004

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Subject:
From:
Franklin <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Wed, 5 May 2004 12:18:41 -0500
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I can't see additional baking relieving warp to begin with.

More than likely it will only add warp.

Warp is typically caused by

1 - uneven balance (coppert weight, prepreg/core thicknesses, etc)

2 - Cross-ply core/prepreg materials.

Some processes may cause "bow" and this may be relieved by heat, but
pressure may also be required, i.e. put them back in your press with some
heat/pressure (but not at original temperatures...).

If warp is present, and you happen to alleviate it, it is only temporary and
will return again as soon as you walk out of the room...

First, determine if you have warp or bow, with bow, all 4 corners are
touching the table/block, with twist 1 or 2 corners are not in contact with
the table/block under normal conditions.

Jeeesh, I think I confused myself...

Franklin
----- Original Message -----
From: "Victor G. Hernandez" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, May 05, 2004 12:09 PM
Subject: [TN] Raw Card warpage


Fellow TechNetters,

   At a PWB factory setting is a final baking process permissible to
correct any warpage prior to customer shipment.   Once the sealed bag is
open and product not used for an extended period of time will the
warpage return.

Victor G. Hernandez

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