IC Handling questions

[jwyles90]

Hey all! I have a question about ICs. I'm curious how you all handle them when you're putting them into your pcbs? I've read that they can be pretty sensitive and can even get fried just from handling them with a little bit of static built up in your hands. 

Do you all do anything when you're holding them to discharge static electricity or are they generally ok? Also, how much bending can the pins take before they themselves become damaged?

Thanks!

[GibsonGM]

What I typically do is - if there are no other special handling precautions in the packaging or data sheet (get and read it!) - just try to hold an IC by its ends at you insert it.  If you hold the 'leg sides', you can bend the legs in, tho sometimes that's unavoidable.  Keep an eye on how things are lining up as you insert it, is all. Don't force them. With practice you can see if it's going in wrong.

I don't use ICs that need special handling; some MOSFETs do, and for that one can get a grounding wrist strap to make sure you aren't holding a charge. I try to avoid handling mosfets on dry days, lol....static...

At times you have to gently bend the legs in to fit a socket...this is ok, but go easy   It's not hard to bone them all up.  You can bend the legs a little a couple of times, maybe using a straight edge - sometimes one goes crazy and is still able to be put back - but try not no or you might end up with a ruined chip.

Use sockets every time, if at all possible! 

[jwyles90]

Super helpful, thanks! Yea I just finished a Klon kit from BYOC and it "works", however there is this kinda gross fizzy sounding crackle at the end of the notes that I suspect might be from one of the ICs. It could also very well be from something else entirely, but it was my first time using ICs so I might have bent the legs a little too much to get them into their sockets

[antonis]

Most of Klon kits are prone to crackling (design flaws..) but ICs aren't responsible..

As for ICs benting, it should be convenient to bent entire column (e.g. pins 1,2,3 & 4 for 8-pin DIL IC) on a flat surface than benting each pin individually..

[GibsonGM]

..and if only one leg gets funny, you can grab it with small needle nose pliers and give it a little bend that way, too! 

[antonis]

..and if only one leg gets funny,

Let it be..

[eh la bas ma]

I think I have been told on this forum that problems with statics are mainly occuring when the circuit is powered. You can touch a component with your hands, even if they are loaded with statics, as long as the circuit isn't powered, as far as i understand.

I always forgot to be cautious and I didn't fry any part so far.

You can "unload" yourself by touching ground on a wall outlet, it's healthy and works also as a luck charm, "Fortune favors the unloaded ones" as they say...

I'm not really sure about all this, though. Did I get it right ?

[GibsonGM]

A charge is a charge, Justin...if you have built up a static charge in your body and touch something like a mosfet, I do believe you can fry its gate.  This is why you sometimes see a protection diode on a mosfet gate, to shunt an unwanted voltage to ground if it is higher than the gate can handle.   This would apply to ICs that have such gates on their input.

Grounding yourself is a good idea, and some use that wrist strap that grounds you before handling static-sensitive parts!   


https://www.informit.com/articles/article.aspx?p=21704&seqNum=3

[eh la bas ma]

Thanks, i'll be more carefull. This article is interesting :

"If you must replace a defective IC, use a soldering iron with a grounded tip to extract the defective IC and while soldering the new IC in place."

Ground the tip of the iron...from what i could find online, it means opening the iron to access the connections inside, and it depends on the model.

I guess this procedure applies in computers and complex circuits mostly ? On stompboxes and IC like TL072, wouldn't that be a bit too much ?

" Before removing the IC from its protective container, touch the container to the power supply of the unit it will be inserted in."

I don't get that part...Why touching the power supply with the IC container ?

[GibsonGM]

A TL072 isn't one of those 'static sensitive' devices,it's FET. I mentioned MOSFETs...there are ICs that are also sensitive like CMOS devices...we don't run into them often, but once in a while we do.   

I've never done anything special for MOSFETs, to be honest...I don't hold them long, and I will hold them by the case, get the legs in the PCB, and just quickly solder them in.   I use a heat sink on them while soldering, which may help keep stray voltages off the gate - I'm not sure. But I'm not a pro, either, and I don't build stuff commercially.   Many of my practices are - non traditional - but I have not had any problems    

[jwyles90]

Yea I would imagine the more common chips probably aren't all that sensitive. I have a couple J201 JFETs that I'm putting into a build soon, so I'll make sure to wear one of those wrist straps or use a pad just to be on the safe side since they were 3 bucks a pop. Thanks for all the helpful info! It sounds like more often than not I'll be fine handling them as long as I'm mindful of how and for how long I'm touching them, but it never hurts to be cautious as well.

[jwyles90]

Most of Klon kits are prone to crackling (design flaws..) but ICs aren't responsible..

Yea I was also wondering if that was just the nature of the circuit. I've only ever played a Klon style OD once before in a store so I'm not super familiar with how they sound in general. The kit sounds awesome when I have the gain anywhere past like, 2 o'clock, it's just on the lower gain stages where it gets a bit fizzy.

[amptramp]

In winter, most places dry out inside, so it is possible to zap a component.  Turning up the humidity might help.

MOS devices including MOSFET's, MOSFET op amps and CMOS logic is susceptible to being zapped by static electricity because the gate oxide is only a few hundred molecules thick.  The way to avoid trouble is to use grounded workbench mats, grounding straps and I have seen some MOS transistors delivered with all leads fed through a brass eyelet.

If you are only handling a few susceptible components, buy extra.  If you are going into production or you have something with a large number of MOS devices, it may be better to invest in anti-static mats and wrist straps.

[duck_arse]

Ground the tip of the iron...from what i could find online, it means opening the iron to access the connections inside, and it depends on the model.

....

" Before removing the IC from its protective container, touch the container to the power supply of the unit it will be inserted in."

I don't get that part...Why touching the power supply with the IC container ?

no no never ever modify a soldering iron. if the specs say it has a grounded tip/barrel, all well and fine. if not, don't try and ground it yourself.

as for touching things, while the part is in an antistatic bag or foam, and you touch the bag or foam, your potential and the bag/foams potential are shorted/equalised/dissipated/something. then you "can" handle the IC pins, because there is no charge difference between you and the part. but don't go silly with it.

[amptramp]

Just an added note:

You will often see components delivered on pink or black foam.  The pink foam is guaranteed to not generate static electricity but it will not discharge any static voltages.  The black foam is guaranteed to be resistive so it equalizes voltages everywhere it comes into contact.  I have saved a lot of black foam for this purpose.

The best way to avoid static discharge sensitivity?  Use tubes.

[GibsonGM]

but don't go silly with it.

^  Sage advice.  I don't mass produce these things, but I don't think I've ever ruined a mosfet or whatever in handling or soldering, YMMV.

Just a bit of common sense is all that's required...my 'work station' has a dedicated ground point for convenience while using DMM etc. I touch that before handling things, maybe it's only for good luck, but it seems to work.   I'm willing to bet the foam has kept me safe on a few occasions.