Rust developing on gold plating in storage...

[aberco]

I dug up a couple chips that have been buried in a box for a long time and noticed a couple have developed rust on the gold plating. How is that possible? any tricks of how to prevent something like this happening?

[mavroxur]

I'd store them with a desiccant pouch or two. More than likely, it's the metal below the gold plating rusting from the excessive moisture.

[aberco]

Make sense, although in Paris humidity is between 20-30%, sometime up to 50%. So I would consider it rather dry.

That P60 was flawless when I got it 15 years ago. I have also a Altera FPGA in same package that developed more rust (I think it had a little bit when I brought it on eBay, but there's much more now). All other chips that are packaged in the box look fine (but they don't have that large gold top).

Will repack the sensitive stuff as you said.

[CPUShack]

30% is high for an IC

10-20 is usually max before issues occur