Another name for "No Clean" is "Won't Clean". 

While No Cleans can have longer stencil life and process windows (almost
like RMA) the residue they leave can be impossible to remove. When you have
rework or do THT which needs to be cleaned you can make a big mess. 

IPA takes water from the air and residues can emulsify and look really bad. 

Bob Kondner

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of N Burtt
Sent: Wednesday, December 17, 2008 9:42 AM
To: [log in to unmask]
Subject: Re: [TN] flux and board cleaning issues

Everyone tells me IPA is a poor solvent for modern flux residues,
particularly 
no-cleans. We do still use it but only locally for rework/touch-up however.

No-clean does not mean no residue, it just means what is left is safe to
leave 
where it is after soldering is complete. Unless the cleaning solvent and
process 
is matched to the residues, you run the risk of making "unsafe" the "safe" 
residues located "safely" on your assembly. Freeing up the reside with IPA
and 
then moving it into every available nook and cranny with compressed air
seems 
unwise to me

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