Can a soldering iron kill an op amp?

Started by acehobojoe, November 20, 2014, 10:32:52 PM

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acehobojoe

So, I have this soldering station from radioshack,.. yes.. I know.. and I'm pretty sure it is the culprit to my mystery op amp killing spree... .they just stop working. :(
it's slightly crappy looking, nice and hot, but I'm pretty sure it's tip isn't grounded and sent power .. very high power. to my JRCwhatever op amp. :o

... is this true? could it be?

sorry for the crap typing, My mind is just a little frustrated.

alanp

I suggest socketing the IC's, and just putting the ICs in the sockets after the soldering is done.

PRR

I've never used a grounded tip, and have not killed many/any opamps that way.

How dry is the air in your shop? Do you get ZAP when you touch the doorknob?
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acehobojoe

I do not, the air is reasonably dry, it's pretty cold now. I just think that it has to be the leakage from the tip. The iron always buzzes when it's on. It's got to be more than a couple of milivolts, and it only happens when I'm soldering something with the circuit grounded.

Keppy

If you're really wondering about the iron, just plug it in and CAREFULLY put a meter on the tip to see if there's stray voltage. Those RS irons take several minutes to heat up, so while you might need to worry about high voltage on the tip, you shouldn't have to worry about the heat if you're quick.

Please note that this advice is restricted solely to irons that take several minutes to heat up. Nobody do this with your instant-on soldering station.
"Electrons go where I tell them to go." - wavley

anchovie

How long do you spend with the iron against a chip leg? If you're hovering there for too long, you'll destroy the internal wirebond that connects the leg to the silicon.
Bringing you yesterday's technology tomorrow.

TheBigMan

I second the recommendation for socketing opamps, I also tend to socket transistors particularly if they are rare/expensive/NOS etc.

Murphy's Law as it applies to electronics in my experience is that you will never kill an part that you are removing from a circuit and therefore don't want, but it's very easy to kill one that you do.  Hence why I have a huge stock of TA75558Ps removed from Tubescreamers over the years.  :icon_mrgreen:

acehobojoe

I really don't put the heat on for that long.The last time it happened I was soldering on the 9 V power rail and I'm pretty sure that it traveled up to the op amp  to ground and killed it.

Another thing to note is that while soldering I have seen potentiometers smoke and spark, but only when I'm connected to ground.

Could you recommend a really good soldering iron or around $80?

And yes, Murphy's Law all the way.

R.G.

Quote from: acehobojoe on November 21, 2014, 08:26:56 AM
Another thing to note is that while soldering I have seen potentiometers smoke and spark, but only when I'm connected to ground.
:icon_eek:

Sparks = significant voltage and/or current.

I highly recommend that you do the test that Keppy recommends. Set your meter to a range of over 120Vac, and connect the black/negative lead to the metal chassis of a plugged-in piece of equipment that has a 3-wire AC plug. If that reads less than about 2-3Vac, change the meter range down from 100V+ to a lower range to ensure that you're reading low volts correctly, and ensure that the low voltage reading is real down on an under-10Vac range. Then flip the meter to reading high voltage DC and try again.

If you get readings over about 1V AC or DC after doing this walking down to low voltage ranges, unplug the iron and CUT THE AC PLUG OFF THE POWER CORD AND THROW IT IN THE TRASH. It's leaking enough voltage/current to kill things, possibly including YOU.

I use this one:
http://www.frys.com/product/3598004?site=sr:SEARCH:MAIN_RSLT_PG
It's expensive, about twice what you mentioned, but after years of using (and using up!) cheaper ones, I went with Weller because they're the classic name in soldering. It was a quantum leap in easy, smooth soldering, all butter, cream, and silk. But it's expensive.

I found the non-temperature-display version as low as $112 here:https://www.parts-express.com/weller-wes51-soldering-station--372-145
Here's a cheaper alternative:
http://www.mcmelectronics.com/product/WELLER-WLC100-/21-3475
The Weller irons, or other irons that use the same tips are great especially for the availability and interchangeability of the tips. Tips are disposable by design. Check the availability of tips for any iron you buy.

Some possible competitors at a lower price are:
http://www.frys.com/product/8303717?site=sr:SEARCH:MAIN_RSLT_PG
http://www.frys.com/product/6599213?site=sr:SEARCH:MAIN_RSLT_PG
https://www.parts-express.com/stahl-tools-ddss-digital-display-soldering-station--374-300
http://www.mcmelectronics.com/product/TENMA-21-10115-/21-10115
This last may be a good deal. I have not used this specific product, but I have used other Tenma tools, and they are a good, workable brand.

R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

armdnrdy

There's a bit of a problem with the cheaper alternative Weller WLC-100 that R.G. suggested. http://www.mcmelectronics.com/product/WELLER-WLC100-/21-3475

The station is grounded with a 3 prong grounded outlet supplied but...the soldering iron included with the station is not grounded.

I built the station from this traced drawing:



I am using a non grounded Weller iron and have a bit under 5VAC at the tip.

I've been using this setup for a couple of years....and haven't smoked any components so far but...I have been wanting to upgrade the iron to a grounded model. (Weller WP30 or WP-35)
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

R.G.

ACK!

As long as you're doing a new iron, get a grounded tip.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

acehobojoe

Well, thanks anyways guys. I'll probably end up getting the weller suggested.

Glad to know I'm not crazy.

wavley

Quote from: anchovie on November 21, 2014, 02:22:38 AM
How long do you spend with the iron against a chip leg? If you're hovering there for too long, you'll destroy the internal wirebond that connects the leg to the silicon.

One of the things I do for a living is manual wire bonding.  Now granted, we use .7 mil pure gold wire and industry standard is 1 mil aluminum that is doped with silicon so it's a little bit tougher, but not by a lot.  Anyway, for fun I swiped through some test bonds I made with a soldering iron just to see what happened to internal bonds with heat and stuff.  They disappeared is a puff and sucked up onto the tip leaving nothing but the footprints.  Bonds are delicate when it comes to that kind of stuff, but surprisingly they are so low mass that they don't really move with vibration, we throw amps in fedex boxes and ship them all over the world and never had a bond wire fail once from shipping or shooting into space.
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acehobojoe


J0K3RX

Doesn't matter what you did to get it... If it sounds good, then it is good!

acehobojoe

A big thanks to you guys for helping me out again. I am glad for it. Hope to make more op amps as the days progress.

bloxstompboxes

R.G. most of your links would not work for me. However, the WLC100 did come up and is the one I have. I haven't had any problems with it yet and love it. I hold two IPC certifications though, so maybe I wouldn't be a good example.

All this talk about sockets. I thought everyone here was against sockets and that they were not good for gigging and such for fear that the IC or whatever, may work loose.

Floor-mat at the front entrance to my former place of employment. Oh... the irony.

Hatredman

Kirk Hammet invented the Burst Box.

PRR

> thought everyone here was against sockets

Sockets are a total side-issue. Forget that.

I am against - "while soldering I have seen ... smoke and spark".

What R.G. said. CUT THAT IRON UP AND GET RID OF IT!

It's not just dangerous to chips. It is dangerous to YOU.

I don't think Radio Shack's irons are usualy defective like that. I've used them with more or less satisfaction, never a hint of danger. I suspect it is a fluke, that if you get another of the same it will be fine (safe). However I don't see any of the RS-branded irons as "real tools". Since I doubt they can carry Wellers any more, shop elsewhere.
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acehobojoe

radioshack is no longer radioshack.. it is smartphoneshack with a few hobby products that aren't very good quality.