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January 2005

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Subject:
From:
Susan Mansilla <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, [log in to unmask]
Date:
Mon, 10 Jan 2005 19:45:05 EST
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I will use Doug Paul's "famous" quip - It depends.

In an "as polished" mount - you will 9 times out of 100 see no line of
demarcation between the end of the inner layer and the plated hole wall copper.
There are a couple of ways that you will see a line in this condition
1)  when you have gross separations
2)  when you have a very thick electroless deposit.

Now you may or may not see a line in the as polished condition if you have
separation.  That will depend on amount of separation and smearing of the polish
on the surface of the mount.  This is similar to the fact that you will not
see cracking in copper in the as polished condition.

After the metalurgical microetch (50/50 ammonium hydroxide/hydrogen peroxide)
you will have a line if the boards were produced with electroless copper as
the hole metalization.  If "direct metalization" is used, you may or may not
have a line.

Let me know if you have further questions.

Susan Mansilla
Technical Director
Robisan Lab
317-353-6249
www.robisan.com


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