OK, Barry, this is a sure sign that your problem is related to the solder mask.
There are several possibilities, but you may be reasonably sure that either the
cure is inadequate or there is a compatibility problem between it and the flux
or some other chemiical, but this may not be the whole story. Do you use any
chemicals in the wash water? What is the type of solder mask?
It would do no harm to contact the vendor at this stage and start asking
questions.
Brian
Barry Gallegos wrote:
> Brian,
>
> After receiving your email, I did the hot air test. The Milky/Cloudy
> appearance did go away.
> After cool down (couple hours), it has not reappeared as of yet.
> My feeling based on your help is to contact my vendor and discuss possible
> solutions.
> If I am in error please let me know.
>
> Thank you for you invaluable assistance.
>
> Barry Gallegos
> Process wanna-be
> Western Electronics
> 208-377-1557
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]]On Behalf Of Brian Ellis
> Sent: Friday, June 09, 2000 1:51 AM
> To: [log in to unmask]
> Subject: Re: [TN] Laminate condition
>
> Barry,
>
> I'll give you a 90% chance that your problem lies with the solder mask.
> Dry film masks are notoriously poor with some W/S fluxes, especially
> some of the older ones (and 856 is hardly modern). The problem is
> possibly purely cosmetic, but it may be symptomatic of something
> serious, in view of the composition of the flux you are using. Have you
> been able to do SIR or ECMR tests? If so, results? Does the milkiness
> disappear if you take a hairdryer to the boards and does it come back as
> the boards cool off again or after a few days? Which solder mask are you
> using? If you can answer these questions, we may be able to help you
> pinpoint the problem.
>
> Brian
>
> Barry Gallegos wrote:
>
> > 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 andis it acceptable.
> >
> >
> > Any advice would be appreciated.
> >
> >
> > Yours truly, (wana-be guru.)
> >
> > Barry Gallegos
> >
> > Western Electronics.
> >
> > 208-377-1557
> >
>
> ##############################################################
> TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
> ##############################################################
> To subscribe/unsubscribe, send a message to [log in to unmask] with following
> text in
> the body:
> To subscribe: SUBSCRIBE TECHNET <your full name>
> To unsubscribe: SIGNOFF TECHNET
> ##############################################################
> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
> information.
> If you need assistance - contact Keach Sasamori at [log in to unmask] or
> 847-509-9700 ext.5315
> ##############################################################
##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe: SUBSCRIBE TECHNET <your full name>
To unsubscribe: SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
##############################################################
|
