In reply to Ben Lee's query, I would like to add the following:

Temporary water soluble masks may well upset your cleaner particularly if you 
are running closed-loop filtration.

Somone mentioned Techform TC564-1 but be careful, this uses salts, soluble in 
water that will kill your filters in minutes. This may mean running pre-wash 
to drain that may invoke water authority issues for draining.

Alternatives may use "clay" which only serve to "blind" your primary carbon 
filters.

Eg: salt will pass carbon but kill de-ionising resins, mixed or separated.
"Clay" will blind the carbon but be gentle on the de-I's

Peelable latex may therefore be better but generally require longer to cure 
although heat curable versions exist.

Synthetic latex is less likely to de-compose when subjected to solvents and 
other chemistries. Watch for poor peel conditions - ie easy break-up during 
removal. Natural latex works better in this regard.

UV curables tend to present more awkward cleaning demands and require more 
expensive curing set-ups. Bear in mind that as solder masks they should be 
applied at 15 to 20 mils thick and non-uv will typically cure in less than 10 
to 15 minutes at room temperature.

Graham Naisbitt


Concoat Ltd					Email: [log in to unmask]
Alasan House, Albany Park			Tel:	+44 (0)1276 691100
Camberley, Surrey GU15 2PL UK		Fax:	+44 (0)1276 691227


-----Original Message-----
From:	Ben Lee 
Sent:	Wednesday, July 23, 1997 4:31 PM
To:	[log in to unmask]
Subject:	Temporary Spot Solder Mask


We are currently testing and looking at a latex peelable, a water-soluble,
a UV peelable, and a UV water-soluble.

I was wondering what type of temporary spot solder mask was out there and
what type are companies using and why?

 I would also like to know  if there were any problem that occured with the
spot mask during the wave or cleaning process ?


Thank you,

Benjamin Lee


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