Barry,

Years back when the water-soluble fluxes first appeared, many
of the local assembly people experienced this white-ish 
discoloration.  After some testing, we found that the thermal
cure soldermasks (we used HySol SR series) was not 
compatible.  We switched the customer to LPI soldermask,
a semi-matte finish and the residue disappeared.  Might
be too late for your product now, but might help in the
future.

Anne Ledger
EMDS, Inc
[log in to unmask]


> -----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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