How Do You Sort Your 7400 Series ICs?

Hi, Phaeton. I use large conductive foam sheets, and store them numerically in fold-open thick card stock backings to which the conductive foam is glued. Then they can be shelved like large, thin books.

Of course, I've spent a while in manufacturing, and had access to these conductive foam sheets. If you're looking to buy them retail, they're pretty expensive.

Another possibility is storing them in the conductive tubes they're shipped in, but again, that's more a matter of having access. Believe it or not, you can buy them retail, or you can scrounge around for them.

Either way, you really should store them numerically. Much easier to find what you need. If you get serious about this, you could also put min/max numbers on the front of the container to make a note if you need to reorder.

Good luck Chris

On 22 Jul 2006 20:41:14 -0700, in message , "phaeton" scribed:

That's how I'd do it. That way, you get consistent behavior in your designs. When you dream up some bizarre circuit, find the assortment that fits, then design your support circuitry appropriately.

I've tried all sorts of schemes but ended up just sorting numerically, that seems the best compromise. I sort in numbered blocks depending on how many trays I have. e.g. 7400 to 7409, 7410 to 7420, etc HC, HCT, LS, AC etc all get mixed in together. Generally these days you'd use HC for almost everything, with maybe AC for fast stuff.

Surface mount parts will generally get their own sorted rack, unless you have deep racks that fit full tubes.

Grouping together by function can be a pain sometimes. Stick a laminated function sheet on the side of the component rack if you want a quick reference for this.

Conductive foam sheets (cut to size to fit the tray) allow you to categorise within each tray if you want.

Dave :)

I have collected a bunch of plastic parts cabnets over the years and have each drawer numbered from 1-xxx. When I get some new ICs, transistors, or whatever, I put them on some antistatic foam and stick it them the next available drawer. Serveral years ago I wrote a little DOS program so that I can keep track of what is in each drawer. Using the program I can very quickly lookup a part number or search for a keyword, or a parameter in the case of discrete semicinductors. This makes it very easy to maintain an inventory of what I have on hand and actually be able to find something.

Mike

------------------------------------------------------------------------ The odds of a single modest length protein randomly forming is approx

1 in 10^260. By comparison the number atoms in the known universe has been estimated at 10^80 atoms. Figues are from the writings of Nobel Prize winner Francis Crick in 1981.

[snip]

Does it work to slice open a number of antistatic bags and lay them across a sheet of foam? Do you get the antistatic benefits by pushing the pins through the antistatic into the foam?

If you're talking about styrofoam, I'd say stay away from it. How expensive is conductive foam anyway? How were they packaged when they shipped? You can cut up those tubes, too, if you only have a few of a certain type of chips.

If you're really static-paranoid, you could use aluminum foil. :-)

Cheers! Rich

On his head?

At work, I went through all the components in storage and organized them.

I just tossed all the 74xx junk, loose in small drawers, in order of increasing number, showing no distinction to letters. I figure it's narrowed down enough that you can dig through the selection to find the right letters you need.

I also put all CMOS (4000 and 74(H)C) seperately into foam, if not particularly well organized ATM. It's not real nice to put 74HC stuff away from 74**, but it saves a lot of static trouble.

I also sorted some things by function, like another drawer has lots of linear stuff, another has mostly power transistors, another has mostly germanium power transistors, etc...

Tim

-- Deep Fryer: a very philosophical monk. Website:

No. You have to know the difference between "anti-static", "conductive" and "static shielding". "Anti-static" tubes and bags are *useless* for static protection, they simply prevent static build-up within a static safe zone. "static shielding" bags and "conductive" tubes prevent static damage to the device while they are inside, so these are the best choice for storage. Conductive foam is pretty good too, but technically you can still touch the pins and damage the device, so they aren't as good a conductive tubes and shielding bags if you are serious about this. Conductive foam is however fully acceptable within a static safe zone.

A lot of people think that IC's are safe inside "anti-static" tubes, but you couldn't be further from the truth. A proper supplier will ship IC's in anti-static tubes within a conductive box or shielding bag.

Don't ever use styrofoam, even with aluminium covering!

Dave :)

Thanks for all the replies, everyone. As suggested I think I'm going to sort them numerically, after all. I just need to decide if I'm going to pay attention to the letters in the numerical name and sort those out, or lump em all together.

I do have some conductive foam, but I don't know that I've got enough for *all* of these. Not all 7400s are static sensitive though, right? Just the stuff with the "C" in the name? I also have some 'rails' or 'tubes'. I used to have a bunch of them from prev. orders but I don't know what happened to them all 0_o. These didn't come with anything nifty, just 100 pieces all jumbled together in a bag:

That picture right there is exactly how they arrived. Makes me a little nervous about ESD that way, but hopefully they'll be ok. If I don't have enough foam I'll just go to a local Radio Shack and grab my ankles^H^H^H^H^H^H^H^H^H^Hpick some up.

I presume that you cannot buy 4000-series assortments because they are way old, obsoleted, and slowly going away?

Actually, I had my grandmother knit me some clothes and blankets out of steel wool. Works great at blocking all those CIA and Alien mind control signals. ;-)

-phaeton

I noticed that when I was going through stuff. I poked the ohmmeter prods into the foam, hmm, 2-20kohms or so, quite nice. This foam, that foam, oops that's styrofoam wtf *dumps in trash*, but the so-called "anti-static" IC tubes don't conduct at all (the meter stops around 30M).

Tim

-- Deep Fryer: a very philosophical monk. Website:

Those are the only ones you have to be really careful about. The rest can still be killed (you'll probably find an ESD voltage rating (based on some static shock model) in most datasheets), but you don't have to be *really* careful about them, just careful.

For instance, when placing an IC, pick it up, ground yourself to the circuit, and THEN place the IC. You don't want to ground yourself AFTER you already pushed the thing in.

Sure. But CD4xxxB is current, I think. I see -BE's a lot, too.

I don't know about assortments specifically.

Sounds itchy.

Tim

--
Deep Fryer: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

Yes, nice stuff, but in theory not good enough to stop damage in a non-ESD protected area.

You've got to get the "hard cell" stuff too, not that wimpy spongy type!

Correct, they are only "static dissipative". i.e. designed not to build up a charge. They will not stop a charge from going right through the pastic and zapping the chip. Once you take the tube out of your ESD-safe area, they are no longer protected. You can get conductive and/or static shielded tubes as well, they are usually black in colour.

Dave :)

...

Dat foam, dat foam, dat - styrofoam, now heeeear de word o' de lawd! ;-P

Is that really from carbon, or is it some other additive? I'd heard that carbon powder is hell on extrusion dies.

Thanks! Rich

By part number.

Yes. Nothing else makes sense.

Absolutely not. No help at all when populating a board.

If I have anything that's not HC - it's likely to end up in the same tray as the HC version with a note e.g. HC/HCT 7400.

Graham