Storing Electronic Components - Page 1
Forum section: electronics / general

author: helloworld922
author_rank: Regular Contributor
timestamp: December 26, 2012, 07:55:35 pm
content: Currently I'm storing my electronic components in Plano stowaway boxes (something similar tothese). These work well for most generic components such as capacitors, resistors, BJT's, etc.I like these because I can have separate containers for different type of parts, and I can adjust the dividers to fit different component sizes. It's also really easy to scale; I just need to buy more containers.However, these don't work so well for ESD sensitive components. When I buy these components they usually come in ESD shielded bags or some other protection system such as ESD foam+box, but these are usually large and it's quite awkward trying to cram these into the compartments. The alternative is to have a large container filled with components in ESD shielded bags, which is fine right now since I don't have that many, but it will become a problem in the future as I get more.I've thought about getting specifically designed ESD containers so I can dump the components directly into the compartments.I've also thought about cutting/taping some old ESD shielding bags or using plain aluminum foil tape on the inside into the inside of my containers, but I have my doubts as to how well these will stand up.So my question is how do you guys usually store these components? Would cutting/taping shielding material or putting conductive aluminum foil tape on the inside of these generic plastic containers work?

author: JuKu
author_rank: Frequent Contributor
timestamp: December 26, 2012, 07:58:50 pm
content: Real ESD storage units here, properly grounded.

author: gszo123
author_rank: Contributor
timestamp: December 26, 2012, 10:53:45 pm
content: Quote from: JuKu on December 26, 2012, 07:58:50 pmGuess you forgot to add link.

author: Psi
author_rank: Super Contributor
timestamp: December 26, 2012, 11:30:27 pm
content: You can ignore ESD issues entirely for hobby work and just store parts in generic plastic boxes.Note:When i say "ignore ESD entirely" This doesn't mean you can pickup IC's with no care at all. Common sense still applies, but you don't have to go out and buy ESD containers/mats/straps etc. unless you're setting up a proper lab to design/build productsObviously though, if you have static issues in your country due to dry weather etc, then you might need to consider ESD.However, the level most hobbyists go to for ESD is just one antistatic strap in there toolbox which they might get out and use a few times a year on really expensive IC's or if they're working on someone else's project or some expensive kit.

author: UPI
author_rank: Regular Contributor
timestamp: December 27, 2012, 12:32:58 am
content: I use 3 ring binders with plastic coin holding pocket dividers. I keep the parts in 2x3" ESD shielded bags inside these pockets.Here are a couple of examples:http://www.amazon.com/20-Twenty-4-Pocket-Collecting-Supplies/dp/B003A7ML6Q/ref=sr_1_3?ie=UTF8&qid=1356568033&sr=8-3&keywords=pages+coin+bcwhttp://www.amazon.com/BCW-Pro-20-Pocket-Page-100/dp/B000IKFWP0/ref=sr_1_5?ie=UTF8&qid=1356568033&sr=8-5&keywords=pages+coin+bcwThe larger/heavier bags will fall out if I toss the binders around a lot or flip it over upside down, but otherwise they work great for storing tons of small parts.

author: TerraHertz
author_rank: Super Contributor
timestamp: December 27, 2012, 02:15:35 am
content: Quote from: helloworld922 on December 26, 2012, 07:55:35 pmHeh. You're young, aren't you?Rule number one of small storage systems - when you buy, buy twice a lifetime supply. Because you'll wildly underestimate your future needs, and when you go back in a year to buy more they'll have stopped making those particular storage boxes. Thisstillbites me, every time.QuoteOh, you have no idea. If you're anything like the parts collector most electronics people become, your storage requirements will approximate an exponential curve. Mine... I can't even post pictures of my 'storage loft' because it's such a nightmare. I wouldn't want to be responsible for the psychological harm to viewers.At some future stage in my ongoing workshop construction saga I'll be lugging everything downstairs, constructing rows and rows of shelving in the loft, then lugging all the junk back up. At the moment it's floor to ceiling stacks of boxes and stuff, no room to build the shelving.In the meantime, here's my solution to the IC storage subset of the parts storage problem. The objectives are optimizing space efficiency, being able to find things, low cost, flexibility for expansion, and ability to include ESD shielding where needed. Those all tend to be in conflict, but this way works well. I got some lidded clothing storage containers, made internal fixed partitions of thin cheap MDF glued together, then used paper envelopes to hold the components. Write the part numbers on the upper edge of the envelope for visibility. For ICs, for packing density plus protection against ESD and bent pins I stack the ICs then wrap the stacks in aluminium foil. Put a couple of ICs upside down at the bottom of the blocks so pins don't puncture the foil (also makes the blocks more dense.)For stuff like disk capacitors and small transistors stick to one type per envelope and skip the foil except for special cases like ESD sensitive mosfets.Another advantage of wrapping them into blocks like that is that you can write the part number on the blocks with felt pen, then pack several different part numbers into one envelope. When you have small quantities of each part number but many, many different parts, this really cuts down the space.The last two pics are of some earlier storage methods I've used. 2318 is some old analog IC stock, in labeled matchboxes, stacked in an old computer punch cards box. Yes, very old. It's kind of a memento, is why I never upgraded it.2319 is another old system I used years ago - sheets of styrofoam (you can find it for free if you look) with aluminium foil just laid on top, then the ICs pressed into it. The ICs hold the foil in place. Touch the foil with your finger first before inserting or removing ICs.Before I switched to the plastic boxes with paper envelopes method most of my IC stock was stored like this. It was a pain in the butt due to 'fragmentation' - get some more parts but have run out of room on the relevant sheet? Now what? The paper envelopes in channels method almost completely eliminates fragmentation issues.Oh, and if you decide to do something like this, buy alotof the envelopes. Because when you need more, it's very likely you won't be able to find exactly the same size & colour ones and that's f-ing annoying.Parts drawer systems are impractical for ICs due to the large numbers of different varieties. Unless you have a lot of room space to waste on mostly empty storage drawers.If you have to deal with ICs' in bulk, just leave them in the anti-static carrier tubes (or SMD rolls) and store the carriers in stackable plastic crates. For small quantities of SMD ICs in antistatic bags, group by type in suitable sized ziploc plastic bags, packed in stackable crates. Actually, get a stock of many sizes of ziplock bags, they are cheap and invaluable for all kinds of storage. Tiny ones for holding individual screws with note of sequence number and location during complex electronics disassemblies, up to big heavy duty ones for bulky component sets, car parts, and anything you want to store for a while without getting dusty.There's stacks of those plastic containers full of envelopes upstairs, but I recently wanted to buy a few more. That form no longer available.

author: nanofrog
author_rank: Super Contributor
timestamp: December 27, 2012, 09:01:05 pm
content: TerraHertz,Are the IC's in the bottom photo stuck into rigid styrofoam sheet covered in a sheet of aluminum foil?

author: McMonster
author_rank: Frequent Contributor
timestamp: December 27, 2012, 09:24:25 pm
content: I've heard that it is actually a bad idea to use aluminium foil or anything else that has low resistance as it can cause large momentary currents from stray charges that might have had accumulated. And those large currents are what actually causes damage to the silicon. In comparison the traditional foam is conductive, but with large resistance. I would like to see some opinions on that.I will have to build a proper bench soon, for now I'm just using a plain old table and some small component containers, but it's starting to be annoying. Time to get real job and invest some money.

author: TerraHertz
author_rank: Super Contributor
timestamp: December 27, 2012, 09:57:29 pm
content: Quote from: nanofrog on December 27, 2012, 09:01:05 pmYes. As I described. The idea is that despite styrofoam being 'static-bad', the foil shorts all the pins together. So the only ESD risk is while inserting of removing the ICS, where there could be static charge differential between your body and the foil, with the IC providing the discharge path. But that's easily avoided by simply keeping your other hand in contact with the foil. Static charge risks are all aboutdifferentialcharge.McMonster: The Zen of anti-static practice is to visualize the physical world as a set of potential charge carriers, the various insulation barriers between them, and the means for harmlessly equalizing charge between objects. Especially where the objects include static sensitive components.If you train yourself to always be aware of these things, and control your movements appropriately, you don't need to use things like anti-static wristbands and shoe grounding thingies.Of course if you are dealing with really really expensive ESD sensitive gear it doesn't hurt to wear the protection anyway, in case you forget.One bit of gear I have has SMA input connectors rated at +/- 2V input MAXIMUM, it's worth a lot of money, and replacement parts no longer carried by the manufacturer. Extreme anti-static measures are mandatory. For instance one MUST ensure that the center conductor of coax cables is shorted to the braid, and both are hard-connected to chassis ground before connecting the coax to the instrument.Anyway, about the foil - you just ensure there are no 'stray charges'. Touch the edge of the foil with a finger lightly first. It's a 'ground plane' - it would take a very large discharge to a point on it to produce a big enough traveling wave in the foil to achieve pin-to-pin transient voltages big enough to do harm.

author: nanofrog
author_rank: Super Contributor
timestamp: December 27, 2012, 11:31:31 pm
content: Quote from: TerraHertz on December 27, 2012, 09:57:29 pmThanks.I just couldn't tell if it was standard styrofoam, or something else (ESD or otherwise) under the foil. Nice inexpensive idea, which is what I'm after.Have done the envelope thing, but hadn't wrapped IC's in foil before (I tend to recycle ESD packing materials).

author: helloworld922
author_rank: Regular Contributor
timestamp: December 28, 2012, 12:47:04 am
content: Ooh, I love the styrofoam idea. The main thing I'm usually worried about is bent pins, and if what you're saying is true about using the aluminum foil, this could be a very easy way to store those pesky DIP chips.QuoteYep, and yepThe main problem I'm running into is that stuff costs money. I either get components, or I get storage.

author: JuKu
author_rank: Frequent Contributor
timestamp: December 28, 2012, 07:27:37 am
content: Quote from: TerraHertz on December 27, 2012, 09:57:29 pmBad idea. You are assuming the pins don't make a bigger hole to the foil than the pin itself, and the foil actually makes contact during insertion and removal. I wouldn't count on that, but if that assumption holds, you fry "only" the first pin in and last pin out. You wrap a charged styrofoam piece to the foil. Insert a chip. Now, where did that charge go?

author: AndyC_772
author_rank: Super Contributor
timestamp: December 28, 2012, 07:47:54 am
content: Aluminium foil and styrofoam is a terrible idea from an ESD perspective.Components get damaged when large currents flow in through one pin, through the die, and out through another pin. To get a large current, you need a high voltage and a low impedance path for the current to flow through. Styrofoam easily generates and retains the high voltage, and aluminium foil provides the low impedance path. It's a very good way to put components at risk whenever you put them into storage or take them out again. Don't do it.The dissipative foam sold for the purpose of component storage is slightly conductive, so charge can only flow through it very slowly. This limits the current through the device and allows unwanted charge to dissipate safely. Materials like this, used as part of a package of ESD control measures, are the only safe way to store components.

author: TerraHertz
author_rank: Super Contributor
timestamp: December 28, 2012, 05:56:48 pm
content: To JuKu and AndyC - you're both not modeling the situation right. It's true styrofoam is an insulator, and can hold a local charge. However.... it isn't an isolated conductive object with a high overall charge and appreciable free space capacitance. A conductive object brought into the vicinity of the styrofoam surface can only equalize charge with a very small volume of the foam - precisely because the foam is a very good insulator.Result is that even if you were sticking ICs into bare foam, the total charge (coulombs) possible to move from the foam, through the IC to your fingers is very small.But with the foil, it's a much better case. Firstly the foam surface will have been sitting against the foil sheet for some time, and despite the high foam insulation it's not perfect and regions of surface charge in the foam will have equalized via the foil. In the case where a pin goes into the foam but isn't making good contact with the foil, it can only receive the charge from a very small volume of the foam. A volume about .1" in dia, and about the same depth. All of which was already equalized with the foil anyway.The ONLY high discharge currents that can happen in this system, are from a 'human body capacitance to free space' to the foil capacitance to free space. And that's why you touch the foil first before creating any such discharge path through an IC.While you have one hand/finger on the foil, your body and the foil are at the same voltage, and so an IC you're inserting or removing sees zero potential difference.And yes, the pins do make good contact, since they are splayed a bit, not parallel. Also the springiness of the styrofoam holds the foil puncture edges against the pins.I used this system for maybe 20 years, including for a considerable stock of 4000 series logic (very static damage prone) and never had a single IC damaged by static while in these sheets.One advantage of conductive foam over the foil system is that there's little need to touch the conductive foam first (even discharging the foam to yourself via an IC probably won't hurt the IC.)Some disadvantages of conductive foam sheets:- Hard to buy big sheets, you're not getting any for free.- Not rigid.- Can't write part #s on edge.