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Mon, 28 Feb 2000 10:28:51 EST |
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With the caveat that free advice is often not worth what you pay for it....
Water is a polar solvent, meaning it has a charge, the Oxygen keeps a slight
excess of electrons away from the Hydrogen, thus maintaining a charge.
This is not the case with carbon-hydrogen type solvents like say, kerosene,
or motor oil. It is essentially non-polar, or charge free.
Polyimide is more polar than FR-4, containing Nitrogen (which tends to act
like Oxygen, and maintain a charge) and this attracts the water. Polyimide
is more "polar", or charged, and the rule in chemistry is "like dissolves
like", so Polyimide loves water more than its uncharged cousin FR-4.
In Chemistry...
Rudy Sedlak
RD Chemical Company
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