Susan,

You did not specifically say, but I am pretty sure you were
refering to the Chromate etchant as the one which was not good
because it masked cracks and seperations.

In my career, I have known only one PWB Fab house which used the
Chromate etchant.  I would not buy boards from them, partly
because I felt the cross section etchant masked their plating
problems, preventing them from fixing their plating quality
problems.  That was only my personel assessment, one person,
however it may be interesting to know that that Milwaukee area
board shop is no longer in business.

-- 
George Franck
Principal Product Engineer
Raytheon E-Systems
Falls Church Va

On Mar 27,  3:46pm, [log in to unmask] wrote:
> Subject: Re: Microsectioning
...This is a good etchant if you are going to etch 
...and evaluate a bar of copper -
...
...IT IS A BAD ETCHANT TO USE FOR PLATED COPPER DEPOSITS
...
...It will "overetch" the small grain sizes of plated copper
...and mask cracks and separations.
...
...Again it is a good etchant for formed copper, but 
...not the etchant of choice for boards..
...
...IPC test method for microsectioning gives the ammonium
hydroxide
...hydrogen peroxide etchant and that is the only etchant that is
...recognized by the government for all of their test labs.  It
is a 
...nightmare to try and correlate results if the labs do not use
the same
...etchant.
...
...Susan Mansilla
...Robisan Laboratory
...
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