IC chip best practices/sensitivity

[Hossymandias]

*I've done what I think is a reasonable search of a the forums and I couldn't find a question like this. If it's repetitive, I apologize.

Id like to collect some knowledge and advice from the forum users about IC chips. These components have given me more headaches than any other. I've gone though countless MAX1044s and TL07xs, and one or two too many LM308s, 4558s, and PT2399s. I have taken to simply buying multiple backups for each of my pedals, but these things are too expensive to be careless with. So how does one minimize the damage done? Here are some of my questions, and maybe others can add.

Which (popular) components are especially sensitive to static damage?

Which (popular) components are especially sensitive to excess voltage? (I recall the MAX1044 being 10v, which I think was the cause of many of my frustrations with them)

When doing repairs on circuits with ICs, do you remove the chips?

What is the safest way to remove ICs? (especially the 16 pin ones prone to bending pins upon removal)

What is the safest way to install IC chips?

How many of you use anti-static wristbands?

Is there a way to reliably and safely test an IC to see if it has failed?

Okay, I'm sure I will think of other questions. I do hope that this thread is helpful, not repetitive, and not too noobish(?). Thanks for fostering such an incredible source of knowledge for an incredibly fun and rewarding hobby!

*I haven't had the same frustrations with transistors, although I did just build a BYOC flanger with a bad BS107. I've been informed that this is an electro-statically sensitive device even though it wasn't packaged in a static-proof bag or accompanied by a warning, so maybe there is room to talk about trannies as well.

[peterg]

Are you using sockets? If not that would be a good start to solving IC destruction.

http://www.smallbearelec.com/servlet/Categories

[bloxstompboxes]

*I've done what I think is a reasonable search of a the forums and I couldn't find a question like this. If it's repetitive, I apologize.

Id like to collect some knowledge and advice from the forum users about IC chips. These components have given me more headaches than any other. I've gone though countless MAX1044s and TL07xs, and one or two too many LM308s, 4558s, and PT2399s. I have taken to simply buying multiple backups for each of my pedals, but these things are too expensive to be careless with. So how does one minimize the damage done? Here are some of my questions, and maybe others can add.

Which (popular) components are especially sensitive to static damage?

Which (popular) components are especially sensitive to excess voltage? (I recall the MAX1044 being 10v, which I think was the cause of many of my frustrations with them)

When doing repairs on circuits with ICs, do you remove the chips?

What is the safest way to remove ICs? (especially the 16 pin ones prone to bending pins upon removal)

What is the safest way to install IC chips?

How many of you use anti-static wristbands?

Is there a way to reliably and safely test an IC to see if it has failed?

Okay, I'm sure I will think of other questions. I do hope that this thread is helpful, not repetitive, and not too noobish(?). Thanks for fostering such an incredible source of knowledge for an incredibly fun and rewarding hobby!

*I haven't had the same frustrations with transistors, although I did just build a BYOC flanger with a bad BS107. I've been informed that this is an electro-statically sensitive device even though it wasn't packaged in a static-proof bag or accompanied by a warning, so maybe there is room to talk about trannies as well.

All ICs are sensitive to static to some degree. Op-amps are pretty resistant. I believe hex inverters/cmos are more sensitive.

All ICs are sensitive to "excess" voltage. You're basically saying here that the voltage applied would be more than what the IC is rated for. Stay within limits from the datasheet and you'll be fine.

If you use sockets then it would be advisable to remove the IC from the circuit before working on the socket pins so as to avoid overheating the IC itself. Otherwise, I don't think you have to worry about it. With pedals it's not that hard to remove them if they are socketed but not really necessary though either. You are more likely to damage the IC by removing it then working on the circuit itself.

Removal and installation is safest with a socket and using a plastic pick or even a chopstick. I find gently prying from both ends of the IC from underneath is best. Just go from one side to the other lifting it in small amounts each time to prevent bending pins.

I suspect almost no one uses wrist straps with pedals unless you are going digital. You run into ESD, or electro static discharge, issues moreso with digital circuits rather than with analog. Fets are pretty sensitive too. Just don't go rubbing your feet on the carpet when you're working. A good way to cut down on static electricity is a humidifier if you are in a dry area.

The only way to test an ic is to actually try it in a known good ciruit, unless you work for the manufacturer of course.

[anotherjim]

Hmmm, you shouldn't be having that much bad luck. PT2399's yes, but LM308's are pretty robust.

Starting with Static.
All semi-conductors can be damaged by static, but MOS are the most sensitive to it.
I don't wear a strap, or have an anti-static work mat, but I do take reasonable precautions. Ground myself by touching a safe ground, such as the ground clip of a scope probe first. Use tweezers or pliers to handle the parts.

Once in circuit, a device is much safer, but not totally.

The environment is a factor. Static will be a much bigger problem in a dry, air conditioned space. Your clothing, footwear and the floor covering - even your chair, can be static generators. My workshop is a timber building and my part of the world has continual high humidity, apart from a few bad weeks in winter when it's too cold to be humid. I would struggle to generate a serious amount of static.

If you do solder your semiconductors, excessive heating can kill them.

Possible excessive voltage. You could be getting voltage spikes from your favorite bench supply. Too fast to see on a DMM but big enough to harm.

You can get tools for chip removing and lead bending. A simple DIP lead bender is 2 roller bearings flat on a base either side of a metal strip that fits the required width between the pins. You push the chip along the strip and the rollers bend each pin in as it goes thru.

Very high humidity can kill devices. The common plastic encapsulation isn't a perfect seal. An environment that combines high humidity with large swings in temperature can pump moisture into the device.

As for testing, make some simple circuits that use all features of the device. For op-amps, a simple non-inverting unity gain buffer. Keep a chip in the board that you know is good. Remove it so you can test a suspect device in the board but NEVER use the known good one in a project. If you don't have a device that you know for sure works, you'll never know where you are when you seem to have nothing but problem ones. I'm definitely doing this with the PT2399!

[R.G.]

I'll wind up repeating some of the advice you already have. Where that happens, take it as a "+1" for the advice.

Which (popular) components are especially sensitive to static damage?

As noted, all of them to some degree. But static sensitivity was not noted in the industry as a special problem until MOSFETs came into use. Today, all semiconductors are usually shipped in conductive plastic packaging to dissipate static as a result. The correct way to approach this is to assume that your work habits are the problem and correct your actions to eliminate static. The simplest way to do this is to remove your shoes and socks (really!) and wear cotton, not synthetic or wool clothing when working on electronics. This has the effect of making it difficult for your body to take and hold a charge.

Which (popular) components are especially sensitive to excess voltage? (I recall the MAX1044 being 10v, which I think was the cause of many of my frustrations with them)

Sadly, all of them. Logic and other MOSFET based chips are probably worst, if only because they are often damaged by voltages as low as 3V to 5V, depending on their construction. The real answer is to read the datasheet for the parts you'll be using, and know their limits, as well as knowing the power supply voltages you'll be using. Although some parts will survive and not be permanently damaged by voltages a little higher than the "absolute maximum" values on their datasheets, I always pretend that all parts will be killed by even a millivolt above that limit. This tends to make sure that none die. 

I remember the story of a young man who was injured by a train. It scraped his face and broke his nose. He explained to his doctors that he was seeing how close to the moving train he could stand without getting hit.

When doing repairs on circuits with ICs, do you remove the chips?

No. I don't. Since handling the chips is a danger, I leave them in circuit. I also don't use sockets, so I can't remove them easily.

What is the safest way to remove ICs? (especially the 16 pin ones prone to bending pins upon removal)

If they are in sockets, use a thin screwdriver or the whittled end of a chopstick or some such to pry gently at one end, then the other. Actually, this is a crude field expedient. The real answer is this:

Sold here for $2.19:
http://www.mcmelectronics.com/product/DISTRIBUTED-BY-MCM-22-530-/22-530

What is the safest way to install IC chips?

This:http://www.amazon.com/14-16-Pin-IC-Inserter/dp/B0002JEZ2S
or this:

They're more expensive than pullers, but you only have to save a few chips to pay for them. These are under $20 new, you can often get them surplus for cheap, and they work GREAT. This last has a pin straightener too.

As an aside, I'm in that part of my electronics career where my time is worth more than the chips. Unless a chip is very expensive - more than, say , $10 - I don't use a socket, and I remove them by cutting the leads off and then pulling out leads one by one. I also don't lose many ICs, and can tell from the pin voltages whether the IC is a problem. I don't debug by replacing ICs on a guess.

How many of you use anti-static wristbands?

I don't. Take off your shoes and socks and wear cotton.

Is there a way to reliably and safely test an IC to see if it has failed?

Not for the home hobbyist. The best test you can do it putting it into the circuit and seeing if it works. This is not definitive, as there can be defects that don't show up in this test.

*I haven't had the same frustrations with transistors, although I did just build a BYOC flanger with a bad BS107. I've been informed that this is an electro-statically sensitive device even though it wasn't packaged in a static-proof bag or accompanied by a warning, so maybe there is room to talk about trannies as well.

Same comments.

[merlinb]

These components have given me more headaches than any other. I've gone though countless TL07xs,

TL's are practically indestructible! What on earth are you doing to these poor ICs? Standing on them?

[R.G.]

Reversing the power supply polarity does a pretty good job. Sockets make that particular danger worse.

[PRR]

++1 to above.

In the eastern US, in summer, you "can not" kill semiconductors with static. Oh, maybe silk undershorts in wool pants with super-effective air conditioning, but you have to squirm a lot.

In winter is a different story. When the heat came up my school got a lot of "dead keyboards". Almost always they would work again after power-down/up, but static from users hands would lock-up the keyboard's tiny brains.

When I must fondle semiconductors in winter I like to make pasta. Boil a pot of water on the stove, cut the dryness. I also touch the ground-trace nearly constantly, never touch a chip by the legs, and NEVER touch a leg when another lead goes to the board I'm not touching.

[vigilante397]

Reversing the power supply polarity does a pretty good job. Sockets make that particular danger worse.

I've lost a couple LM308's that way 

I used a strap every time I handled ICs when I first got started because my professor scared me into thinking the world will end if I touch an IC without one. But now I pretty much follow all the advice listed above.

[bluebunny]

I used a strap every time I handled ICs when I first got started because my professor scared me into thinking the world will end if I touch an IC without one.

I used to do this when building PCs.  Now I just throw them together with (almost) careless abandon.

"Famous last words", of course...   

[merlinb]

Reversing the power supply polarity does a pretty good job.

That's not really a question of "proper handling" though, more general ham-fistedness!

[amptramp]

One thing to mention, especially with MOS devices is that static damage can be limited to the point where there is just an increase in noise and greater susceptibility to further damage without causing it to stop functioning.  For example, most power MOSFET's have a ±20 volt Vgs maximum rating.  Static damage may reduce this rating without rendering it unusable right away and if the circuit does not push limits, it may function normally but will be much more susceptible to further damage.  This is a latent defect - it does not show up right away but just stays there, waiting for its chance...

[R.G.]

Seriously, folks - to eliminate static buildup, take off your shoes and socks. Feet are conductive, shoes are often not. Conductive feet don't build up static like any shoes do. Think about static sparks when you shuffle across a carpet in a heated house in the winter. You can't do that with bare feet.

In the winter when heating boils out all the humidity, as Paul says, put on some water to boil to put some humidity back in, or work in your bathroom with the shower blasting hot water. Both put water back in the air. Static buildup can't happen with humidities above about 40%.

Discharge yourself before touching semiconductors directly by touching something that's grounded. Touching the conductive plastic bag, tube, or black foam the semis are in and letting your charge equalize with the semis is very effective too.

Just think about what you do to get a good carpet-static zap, then don't do it.

[Mark Hammer]

Phentex slippers on a shag rug in a wool turtleneck sweater is...not a good idea.  I don't care if your grandmother made you the slippers and your mom or partner made the sweater.  Get 'em off.

And if you're going to drain static charge off your body, make sure that when you touch the sink you aren't touching the chassis of an amp that has a polarity-reversal switch on it at the same time.  "Ground" is where you want the excess charge to go, not where you wish to go yourself.

And while I encourage caution over foolhardiness, my own experience is that many static-damageable chips are surprisingly hardy.  One may acquire them in circumstances that make you think "There's no way it could have survived that!", and sonuvagun, they work fine.

So by all means be careful, but don't drive yourself nuts or panic unnecessarily.  Me, I'm more concerned that the markings get scratched off the chip or become illegible, and I'll have a "good" chip that I won't know what to do with.

[scratch]

the other option is to work on a anti-static mat of some kind ...

you can roll your own using large anti-static bags (metal foil looking ones) and connect a wire through a 1M resistor to ground  and an alligator clip to clip onto the bag

mine is made from a sheet of stainless steel that came out of an old ibm printer going to scrap. Took a three prong extension cord connector (took the blade out out for the live side for extra safety), put my 1M resistor inside, soldered wire to other side of resistor, then out to my plate.

[CodeMonk]

Seriously, folks - to eliminate static buildup, take off your shoes and socks. Feet are conductive, shoes are often not. Conductive feet don't build up static like any shoes do. Think about static sparks when you shuffle across a carpet in a heated house in the winter. You can't do that with bare feet.

In the winter when heating boils out all the humidity, as Paul says, put on some water to boil to put some humidity back in, or work in your bathroom with the shower blasting hot water. Both put water back in the air. Static buildup can't happen with humidities above about 40%.

Discharge yourself before touching semiconductors directly by touching something that's grounded. Touching the conductive plastic bag, tube, or black foam the semis are in and letting your charge equalize with the semis is very effective too.

Just think about what you do to get a good carpet-static zap, then don't do it.

All of what RG says...


Then there are these as well:
https://www.google.com/search?q=disposable+anti+static+foot+straps&espv=2&biw=1366&bih=643&source=lnms&tbm=isch&sa=X&ei=dOk9VNHNNYS8igLgs4CAAg&ved=0CAgQ_AUoAQ#tbm=isch&q=anti+static+foot+straps

Often, at many places I worked at in the 80's we used a one time use, disposable foot strap.
It was just a cheap looking anti static strap that would wrap around your shoe and you would stuff the 2 ends into your socks so they would make direct contact with your skin.
You probably know the kind I'm talking about RG . I couldn't find any pictures of them though.

We used those in addition to the wrist straps.
Although I didn't use a wrist strap when I ran wave solder machines. Wrist straps are not really practical or safe in that environment.
Just used the foot strap.

[greaser_au]

Although I didn't use a wrist strap when I ran wave solder machines. Wrist straps are not really practical or safe in that environment.
Just used the foot strap.

Agreed...        (Hollis user from WAY back!)
david

[CodeMonk]

Although I didn't use a wrist strap when I ran wave solder machines. Wrist straps are not really practical or safe in that environment.
Just used the foot strap.

Agreed...       (Hollis user from WAY back!)
david

You memory is better than mine.
The last one I ran was from 1982 - 1985 and I can't remember the brand, although the image of it is as clear in my mind as if I ran is yesterday.
Some video company did a safety video that included showing me running the wave solder machine (around 1983 I think), so maybe there is an ancient safety video with me out there running that thing.

Holy crap...did a search. My last one may have been a Hollis as well.
https://www.google.com/search?q=hollis+wave+solder+machine+history&es_sm=122&biw=1366&bih=643&source=lnms&tbm=isch&sa=X&ei=HWs-VJfPOM-MoQSVsIEw&ved=0CAkQ_AUoAg
Same color scheme as the first result and similar design.
The opposite side was fully closed (But had windows) and the flux bubbler was on the outside IIRC. And it had the vent right over the solder bath.
(Sorry to go off topic. but every now and then I feel nostalgic and actually looks for pictures of that thing).

Edit:
Come to think of it, the other side had the the controls and the tray where you would add solder and remove the dross, as well as the drain I believe.

[greaser_au]

The last one I ran was from 1982 - 1985 and I can't remember the brand, although the image of it is as clear in my mind as if I ran is yesterday.

I'd say we are of similar vintage then...

The Hollis wave machine I drove had 2 aluminium rails, one with an inset chain drive (boards mounted on frames with a pin to engage the chain). A bubble fluxer that made Mr Multicore's solvent division very, VERY happy.  A preheater tunnel and a 1/4 ton capacity solder bath with a 1HP motor driving a submerged pump - it was important to get that oil ratio right - I have the scars to prove it!!!

I ran a 'drag' machine and a vapour phase reflow machine there as well - all before 1990!

david.

[CodeMonk]

The last one I ran was from 1982 - 1985 and I can't remember the brand, although the image of it is as clear in my mind as if I ran is yesterday.

I'd say we are of similar vintage then...

The Hollis wave machine I drove had 2 aluminium rails, one with an inset chain drive (boards mounted on frames with a pin to engage the chain). A bubble fluxer that made Mr Multicore's solvent division very, VERY happy.  A preheater tunnel and a 1/4 ton capacity solder bath with a 1HP motor driving a submerged pump - it was important to get that oil ratio right - I have the scars to prove it!!!

I ran a 'drag' machine and a vapour phase reflow machine there as well - all before 1990!

david.

Sounds just like mine almost to a "T" except we had a 3 - 4 foot iron plate that preheated things.
And there were a few times I didn't get that pin put in just right and after a few inches, it would "drop" in. What a mess. Parts everywhere.
And we used water soluble flux which made whatever company made our board washer happy.
And we didn't have any oil in the solder. We just poured dross retardant to separate the impurities a few times a day into the tray (Which was just a small part of the bath that stuck outside the enclosure). Then spoon the impurities out.
Although the one I ran at Litton did (And I have those scars as well, one of which gave me the rest of the day off, which I spent at the nearby bar (After getting my pain meds at the occupational center of course).


Still as hazardous as it could have been and how much you had to really be on your toes, it was a great job.