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Subject:	Re: Laminate condition
From:	"Denis J. Dionne" <[log in to unmask]>
Reply To:	TechNet E-Mail Forum.
Date:	Tue, 13 Jun 2000 13:01:38 -0400
Content-Type:	text/plain
Parts/Attachments:	text/plain (54 lines)

Try baking the stained board at 300 oF for 60 min immediately after the
cleaner as a test, if it gets rid of the stains you may very well be looking
at moisture.  To prevent it, do look at the solder mask cure, a UV Bump will
prevent this but you may also want to look into your temperature going into
the washer, keep it low (talk to your SM vendor or board supplier).  I just
had a similar issue here.  Apparently most SM will 'open up' under high temp
and absorb some moisture and exhibit 'hazing' or white staining.

Denis Dionne
Coretec Inc.

> -----Original Message-----
> From: Barry Gallegos [SMTP:[log in to unmask]]
> Sent: Thursday, June 08, 2000 2:14 PM
> To:   [log in to unmask]
> Subject:      [TN] Laminate condition
>
> Dear Sirs, Madams, Guru's.
>
> I have an assembly that we processed thru SMT and then thru the wave
> solder operations. Wave solder flux was with Alpha metals 856
> water-soluble. The assembly is exhibiting a white cloudy / milky
> appearance that looks almost as if the laminate/solder mask has changed
> color. No matter how much we wash this assembly, it will not go away.
>
> Is this due to possible moisture in, around or under the solder mask /
> laminate. What is it and  is it acceptable.
>
>
> Any advice would be appreciated.
>
>
>
> Yours truly, (wana-be guru.)
>
> Barry Gallegos
> Western Electronics.
> 208-377-1557
>

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