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From: [log in to unmask]
To: [log in to unmask]
Subject: Delamination
Date: Monday, May 27, 1996 9:37AM

We have detected a large delamination on all boards from one of our
production batches. This delamination appears in the SMT IR oven (short
wave) step in our customer facility.
Curiously the delamination takes place between black oxide and base copper
interface. In other words, the black oxide layer peels away from his own
base copper and remain stick on epoxy resin. The stripped Cu appears pink.

We suppose that we made a mistake in B.O. process but we don't know where
exactly.
Our B.O line has de following steps:
Sodium persulfat microetching
Black oxide (Shipley)
Oxide reduction (Shipley)
Antitarnish and rinse
Hot air drying.
Did somebody hear about this kind of delamination?. If yes, which is  the
B.O. wrong parameter?
Excuse my English.                                                thanks in
advance.

     José Muelas

Recommend checking your cleaning process, ensure no chlorides are present 
prior to BO.


                                                           M. Harris