Hi Pete,

There is no playing on BGA balls but ‎their surface will oxidize over time. Baking will speed it up. 

You can easily calculate for how long and at what temperature to "age" the package to mimic 5 years of storage and then try to solder few of those to see what to expect in 5 years.

Regards,

Vladimir

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  Original Message  
From: Peter G. Houwen
Sent: Tuesday, April 7, 2015 09:54
To: [log in to unmask]
Reply To: TechNet E-Mail Forum
Subject: [TN] 5 year old BGAs

We have an FPGA that may not be available to us soon. One of the options available to us to avoid a redesign is to buy 5 years' supply of the BGA.

I'm being asked to analyze the risk factors (and we need an answer today of course)

We can easily bake parts for moisture, but what about plating degradation on the balls? Any other problems I might expect?

I assume that even with baking we should expect some yield reduction, but I can't begin to guess how much.

Thanks,

Pete

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