Corrosion/rust/discoloring on ES cpu

[JAC]

Compare it to the picture you have taken for your site?

[debs3759]

WD40 can corrode some metals, so I wouldn't advise that. Having a film of grease or oil on a static metal part (or any other part, when I think about it) can trap moisture or other substances on the surface you meant to protect, whereas on moving parts (such as engines...), that is not a problem as either heat or movement will help remove the moisture.

I don't know however what is good, only what is not.

[debs3759]

Personally, I would never recommend using grease or oil to try and protect a chip, there are too many unknown and unpredictable factors. Of course, if anyone knows of a particular lubricant that is known to be safe, I'd love to hear about it (especially if there is scientific evidence that it does not carry the same risks as many other lubricants).

[JAC]

lubricant? lmao

[debs3759]

LOL, I thnk you read that differently to how I meant it

[chip68]

Yeah, I've seen chips with fingerprints permanently etched into their lids from contact with oils on the skin, which traps salts and other corrosives. The only thing I would recommend is to store them in a cool, low-humidity environment and keep your fingers crossed. I have many chips that are over 40 years old that look brand new, while some much newer ones already have visible pitting or oxidation of the exposed metal surfaces. It's a crap shoot, really.

- CMW

[chip68]

Rust requires iron, which is typically only used in IC packaging alloyed with nickel in the form of Invar or Kovar. Neither oxidizes readily. Gold is non-reactive; aluminum and silver develop a patina that inhibits further oxidation; lead and tin (in solder) do oxidize to some extent, but that wouldn't be what you're seeing. Is this just a discoloration, or are there signs of pitting and/or flaking?

- CMW

[x86sniper]

corrosion / oxidation will not spread in a totally dry environment, it requires water vapour (i.e humidity) to spread, which is the case I am facing

Hong Kong isn't the best place to store CPU espacially when my flat is near to the harbour front, the high humidity of the weather and the salt content in the air acclerate oxidation to a amazing level

Simply put a naked goldcap Pentium for a few weeks and you will see white dots all over the supposed-to-be gold
(even socket 423 Pentium 4 oxidize, too )

to overcome this I suggest some method.......

for CPU that is oxidised already upon you receive it, use ball-pen eraser (those erasers that is very hard and perform like a sandpaper) first to rub away all those oxidations, DO NOT let oxidation left on the metal surface, sandpaper also works but personally eraser is easier to control and go into some tight corners

after that some storage method can be taken, you can choose any of them according to your needs
1. store chips in mainboard boxes (works if you have a relatively dry place e.g wooden cupboard / drawer)
2. wrap chips individually in newspapers then go into paper boxes, tissue papers also works
3. use polystyrene foam to cover the metal surface (best if use closed foam instead of expended)
4. for some OEM CPU that freshly pull from machines, they usually got thermal greases and/or a piece of aluminum sheet onto the metal surface, those CPU resist to oxidation for a short time if thermal grease / al sheet not removed immediately
5. for some CPU come with a heatsink with reusable thermal tape interface, keep the heatsink in place, it helps to block oxygen from come into contact with the metal surface

[x86sniper]

[chip68]

[x86sniper]

[JAC]

[JAC]

Time to read up on some chemistry!

[Mixeur]

chiptalk, can you take a photo of your chip ?

[wepwawet]

What about this.
My guess is that a try to clean the rust will result in a total damaged lid.