I have heard of instances where it was suspected to have happened, but not in the past 10 years or so. It is a very rare occurance, but it could happen if the package is not hermetically sealed. It depends........Ka-chink. 
The Diet Dews are going to be rolling in to Mr. Pauls. I saw a Diet Dew truck going south on 35W today, going the wrong way, I thought. But then I remembered.......

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Dale Ritzen
Sent: Wednesday, February 11, 2015 4:25 PM
To: [log in to unmask]
Subject: [TN] Incursion of fluxes into electronic device packages

Hello Technetters,
Has anyone ever experienced issues with solder paste flux (or potentially flux from cored wire solder or wave solder or selective solder processes) penetrating into a chip package during reflow or cleaning or whatever? One of our customers has asked about it and I know of no incidents like this. Their question applies to all types of flux in general. But, I thought someone out there may have run across this in their travels. 

I'm trying to figure out just how that could possibly happen with all the package retooling for the higher temperature RoHS processes, but I will rely on your vast experience and knowledge to provide the right answers.

I am waiting for all the "It depends..." answers to start rolling in!

Thank you in advance,
Dale Ritzen, ASQ CQA
Quality Manager / ISO Management representative _____________________________ Austin Manufacturing Services

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