semi OT - storing IC's

[Mcgyver]

I picked up a box of electronics parts cheaply. Lots of IC's many just stored in bags (cmos/ttl/PIC's etc). Some/many/all may be shot, won't bother me, it was still a good deal for the rest of it.....but is tinfoil stretched over styrofoam a reasonable way to store them? I don't have enough of special foam and wanted a large area to start sorting them out on.
thanks

[Forestgnome]

No, that's not a good method. The black foam is resistive, and dissipates static electricity slowly. Aluminum foil will conduct the charge directly to the leads. If you have to, ht plain styrofoam would be better than the foil idea. At least the leads would be insulated from contact. Just so you know, I'm an electronics tech at a major test equipment company, so I'm qualified to make that statement.

[ldn]

No, that's not a good method. The black foam is resistive, and dissipates static electricity slowly. Aluminum foil will conduct the charge directly to the leads. If you have to, ht plain styrofoam would be better than the foil idea. At least the leads would be insulated from contact. Just so you know, I'm an electronics tech at a major test equipment company, so I'm qualified to make that statement.

I'm pretty sure it's just the opposite. Styrofoam alone is death to ICs.

Styrofoam is a source of static. The Al will keep all the leads at the same potential, preventing discharge through the part.

Al over Styrofoam is bad because you can easily end up with a lead that goes through the Al but doesn't touch it.

If the OP doesn't have any IC tubes or antistatic bags laying around, I'd say that an Al lined cardboard box is a pretty good way casually store ICs of no real value.

[Black_Moons]

Just buy more special IC foam :)

[PeteF]

My "past life" was in this field, and also worked on the retail side of the counter while I was studying. Back in those G.O.Days the foil/foam method was sometimes the way ICs were actually sold in retail! They'd come to us in tubes and we'd put them in foil/foam so we could just use a knife to slice off the foam containing the number of ICs the customer wanted. I've seen literally thousands (tens of thousands??) packaged up and sold that way. Plain Styrofoam is a bad idea due to the static issues as discussed. The problem, as pointed out, is that there is the potential for a lead to go through and not touch the foil. In practice I've NEVER seen that happen if you push the pins through "virgin" foil. It's definitely a possibility if you take the IC out, then try to push it back into the same holes it came out from.

Pete

[Evan]

You wouldn't rely on poking a wire into a piece of foil covered styrofoam to make a decent connection for any other purpose. Don't rely on it working for storing ICs either. If a pin is floating then any charge that hits the foil can fry it, especially if it is an input.

[Your Old Dog]

Maybe you could hit a few computer stores to get the anti-static plastic bags they ship mother boards in. It would be better then foil and Styrofoam.

[Forestgnome]

I'm pretty sure it's just the opposite. Styrofoam alone is death to ICs.

Styrofoam is a source of static. The Al will keep all the leads at the same potential, preventing discharge through the part.

Al over Styrofoam is bad because you can easily end up with a lead that goes through the Al but doesn't touch it.

If the OP doesn't have any IC tubes or antistatic bags laying around, I'd say that an Al lined cardboard box is a pretty good way casually store ICs of no real value.
Yes, styrofoam can store a charge, which is why it's verboten at a static-safe workstation, but if the ic is stored in it, there's already a steady discharge path through the leads which equalizes the voltage. It's all about where the charge comes from, how big the charge is, where it goes, and how fast the discharge is. I used to work in the driest climate on earth before ESD protective equipment was on the market, and there are ways around it if you understand static electricity. I'm not saying styrofoam is a great idea, just better than the foil idea. Actually loose in the cardboard box is probably better yet. Obviously if you can follow industry-standard procedures that's the best idea.

[Mcgyver]

You wouldn't rely on poking a wire into a piece of foil covered styrofoam to make a decent connection for any other purpose. .

that's a good point. otoh, sheets of foam are not as cheap as i might have hoped and will require a trip....anything that avoids a trip is good in messed up Toronto traffic. I guess i was hoping for the cheap ready solution, as per usual not always the best

Tube's are out, I find the faintness and size of the characters problem enough to read without the plastic's distortion. maybe I'll find some foam at one of the surplus places.

thanks all for the help

[Weston Bye]

I have a set of shallow wooden drawers (a sales display for artist's pastels)that I lined with black conductive plastic from an ESD bag. The chips just sit on top of that, and I only open the drawer or handle the particular chip that I need. This is for the MOS chips. The TTL chips are in the same cabinet, but I haven't bothered with antistatic protection, and haven't had a problem in 30 years. (knock on wood)

Lately I've taken to lining the individual compartments of Plano boxes with pieces of mylar antistatic bags for some of my supply of chips.

[lazlo]

Michael, I can send you several electrostatic bags and a bunch of black ESD foam if you want.

[Evan]

I'm a charter member of the "Never throw anything out club".

Robert, You send foam and I will send some ESD bags if they are wanted. I have a few extra.

http://ixian.ca/pics7/esd.jpg

[KIMFAB]

Looks like I've been beaten to the punch on the foam and bag donation.
If you need more give me a holler.
I just store the old 7400 non cmos in plastic boxes but if you want to get fancy you might check this.

http://in.mouser.com/Tools-Supplies/Anti-Static-Control-Products/_/N-5gg4?Keyword=anti+static+container&FS=True