The structure of the polyimide has a lot of twist turns and folds this gives
the polyimide a lot more surface area then standard FR4. The polyimide
chemical structure is also quite a bit hydrophilic (i.e. it likes water and
water likes it) therefore it does accumulate water more readily then FR4.

Hope this helps,

"By the way no fair for the "AD penalty"... I can't go to APEX... :-(

Alain Savard, B.Sc.
A lot of English people call me "Al" and  I am a Chemist... so I am an
Al-chemist
Chemical Process Analyst
CAE Electronics Ltd.
e-mail: [log in to unmask]

-----Original Message-----
From: Guenter Grossmann [mailto:[log in to unmask]]
Sent: February 28, 2000 5:00 AM
To: [log in to unmask]
Subject: [TN] Polyimide


Hi all

Got a question for the alchemists. Why does Polyimide absorb so much water ?


Have a great day

Guenter

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