hmmm  ....
i assume the white spots are all over the solder resist. in the case there is no anorganic/ionic residue, i would say, mobilized by humidity and temperature  higher alcohols or solvents or uncured reaction products contained in the solder resist diffuses through the material (in this case the solder resist)to surface, and leave the noted withe spots. may be "only" a cosmetic problem, avoidable by air knife. Better to assure proper curing of the solder mask. however, to assess the risk (recomended only in the case of hi-rel application and/or additional application of conformal coating)a electromigration test and/or a adhereance test of the conformal coating should be performed.

Bernhard Wanner

----- Original Message -----
From: <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, June 18, 2002 1:42 PM
Subject: [TN] Washing Semi gloss boards.

> Hello fellow Technetters
>
> I have been reading the postings for a long time, thought this would
> be a good place to get my questions answered. I have an Aqueous
> technology batch cleaner. The cleaner washes the board then go into a
> drying cycle. It is a closed loop system with a 5 micron filter.
> Everything I use in my process is water soluble.
> Everytime I wash semi-gloss finish boards there are water spots all
> over the boards.
> Mat finish boards come out spot less.
> Has any one experience this before ?
> Why is this happening ?
> Do I need to add any chemical or solvent to the water?
>
> Any comments would be greatly appreciated.
>
> Thanks in advance
> Carl.