Hi Nancy -

Electromigration is fairly well documented in IPC-TR-476 and IPC-TR-476A.
The basic causes consist of the combination of differing circuit potential,
moisture and a contaminant.  I've watched dendrites form between tin/lead
coated traces .050" apart at differing potentials as low as 5mv.

Check TechNet archives over the past six months for quite a number of
dissertations on the subject or Email me direct for further info.

Regards - Kelly
-----Original Message-----
From: Nancy Trumbull <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Friday, October 01, 1999 9:11 AM
Subject: [TN] Electrical Migration


Hi Every One.

I need information on Migration

Question
1.  What will cause Electrical Migration

Reason :

We are seeing Dendritic Migration between components

As of now we are applying conformal coating trying to stop the migration.

Question:

1. Is there a rework to prevent this condition.

2.  Any study or data out there on reliability as far as using this method
to stop the migration.


Any information at all will be greatly appreciated.
If more information is needed please ask.  This is all I know as of now
I will do my best to get what ever is needed.

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