Foil on foam might be better than no solution at all. It was used in the very early days of CMOS IC's and it sort of works. The problem with the foil is that it is conductive rather than dissipative. The difference being that dissipative materials like antistatic bags and foam gently leach away the charge while with conductive metal foil the charge is zapped away. Zaps are not good for CMOS.

On the other hand, being a hobbyist making one or a few of something is different from running a factory in which you will make hundreds of thousands of something each day are very different. If a hobbyist has an ESD problem it cost a few dollars and a few days, but if a manufacturer starts getting returns from the field of only a small percentage of units, that is a real problem.

Hi,

That is an interesting observation, anti static vs conductive foil.

One of the other problems i noticed with foil is that once the IC pin hole forms, it might enlarge with some movement and thus not make contact anymore. That always bugged me.

I keep the IC's in the original packaging until ready to use, but then again i get most of my stuff from places that know how to ship properly.

One time i got a somewhat expensive PC board with NO anti static packaging whatsoever. I freaked out when the board didnt work, and emailed the seller and pretty much told them off pretty good. Later i found out the reason it did not work was because the wire lengths i was using were too long for the frequency. My bad, but i did not let them slide on it anyway and told them they better learn how to ship properly. If it was shipped properly i would have never freaked and would have looked into it more carefully before emailing them.

So word to the wise, use sellers that know how to ship to begin with and use the packaging they provide which is usually good.

I have parts from the mid 1970's and they still work, and even a few (not many though) earlier than that. I keep my stuff stored as safely as possible.

 

Don't use those black sponge foam (example in the top image). The moisture content is too high and results in accelerated corrosion.

Now you tell us! Why didn't somebody tell us this 45 years ago!? Wait...why are weholding on to such old CMOS logic parts?

 

I've never had problem on chips but stuff thats not so easy to cheap had messed up a time or too pulled ram from pc stuff like that.

 

Don't use those black sponge foam (example in the top image). The moisture content is too high and results in accelerated corrosion.

Hi,

There must be a big difference in foam or the environments the chips are stored in and maybe the type of container also.

I say this because i had some chips for a lot of years. From around 1980 which is almost 40 years now. Never had one chip corrode like the pics in this thread. Not one.

Maybe the foam made back then was better or something?

I also have some stored in those anti static "tubes' where the IC's slide down inside the tube from one end then you block the end with something so they dont slide out. They also protect the shape of the pins.

 

Now you tell us! Why didn't somebody tell us this 45 years ago!? Wait...why are weholding on to such old CMOS logic parts?

Hi,

Do you have any that had corroded? I dont and i've had some for almost 40 years in foam.
Dont know what the difference is, foam or environment.

 

Hes, some logic parts from the mid-1970's are a little bit dirty with corrosion of the surface and bits of the black stuff attached to the pins. These chips have been stored in many environments from desert to the tropics, so can't pin down what if anything the environment has to do with it.

 

Firstly, No. Not at all
Secondly, I believe those two first chips on the left are fakes

 

Yes, some logic parts from the mid-1970's are a little bit dirty with corrosion of the surface and bits of the black stuff attached to the pins. These chips have been stored in many environments from desert to the tropics, so can't pin down what if anything the environment has to do with it.

Hi,

Oh ok. Well my stuff has been in the Central Jersey location for the last 40 years so whatever weather we had here that's what they got, except i keep them in either a plastic box also or a cardboard box and the parts are usually kept inside another regular plastic type baggie as well as the packaging they came in.
So some parts are in a plastic box with a non sealing but decent cover, also in their original packs, and some are in larger plastic baggies also in their original packs and also the baggie is inside a cardboard box.
One, but only one, set of parts that includes at least one 8080 CPU and one Z80 CPU is in a wooded cigar box but it's a really good quality box, and they are stuck into black conductive foam that parts often ship in.

That reminds me, some parts have a recommended soldering technique that includes a humidity reading and they even ship a humidity test strip with the parts sometimes. If the humidity isnt right the part should nto be soldered to a PC board yet. The strip came with a couple SMD LED's i bought some time ago.

Now that i think of it, i dont think i ever had a rusty IC chip. Bent leads yes, rusty no.
I have had rusty pieces of metal (mild steel) though that i bought in various places. Some get really nasty when they sit for years.

Maybe i dont see rusty chips because i always keep them in a secondary container of some type that although not air tight is better than nothing.