Ian

I believe that J-STD001A and B call up for a level that should be lower than
10.07 micrograms/square inch = < 1.5 / square centimetre.

Do bear in mind the following:

1  There are many types of ROSE / SEC testers each of which have different
interpretational values (that is to do with calibration). You must ask the
manufacturer of your system to provide you with the equivalency factor.

2  The standard was always intended to be a production control guide. Never
a pass / fail criteria.

However, as you and many others (including the DOD) seem intent upon
applying a pass/ fail, remember that the spec is also saying that it is
acceptable to leave UP TO 10 mg of NaCl equivalence on every square inch of
your assembly. If you are dealing with fine line/fine pitch, COB, BGA and
other such stuff, I think this level will almost certainly prove too high.

Hope this helps to stir things up...

Regards,
Graham Naisbitt

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----- Original Message -----
From: Ian Boyton <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, July 08, 1999 4:53 PM
Subject: [TN] Ionic testing for contamination


> Hi all
>
> Can anyone tell me what the industry std/limit is for micro grammes of
NaCl
> per sq cm found after ionic testing?  I have a value under 5 and have a
set
> fail limit of 20ug. This is after a 20 min test.
>
> Best Regards
>
> Ian Boyton
>
>
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