FETs and ungrounded soldering iron

[Navyblue]

Ok, I soldered some JFETs with an ungrounded soldering iron.

So guys, in your experience, what's the chances that they are still alive?

I also soldered some BJTs with it.

 

[NelsonVandal]

I'd be very surprised if they're fried. I'm a transistor (and opamp abuser) of ranks, and I've never ever destroyed a JFET transistor, nor a JFET input opamp. I've soldered transistors with power on, swapped transistors with power on. I'm often A-B'ing capacitors while playing music and experimenting with feedback resistors etc live. I've run transistors burning hot. I've run opamps at twice their rated supply. Very rarely something dies.

Some parts are more prone to die of abuse. TLE2426 is quite sensitive, and I've destroyed a bunch. Running output transistors without emitter resistors is asking for trouble. ADA4899-1 and AD8099 are easily killed by too high voltage supply. Old tanalum capacitors can't withstand their rated power spec's and burn.

Anybody destroyed anything else?

 

[FallenAngel]

It's not easy to burn opamps, believe me I've tried.

Did find out a surefire way of killing AD8397's though, just reverse their voltage. Beside that I've done it to many opamps, still didn't cook. Caps on the other hand, ooh, they love being powered on in reverse. Had lots of fun with tantalum caps that go flying in all directions and electrolytic caps that blow up with quite a bang of reverse voltage (though they do give you some warning, they puff up and smell a bit first) while tantalum just blows.

 

[Navyblue]

Ok, I feel better now.

How about MOSFETs?

So in practice grounded iron is just a good feature to have? Most text book seems to suggest that ungrounded soldering iron with ceramic element is a no no for FETs.

 

[amb]

Proper ESD handling practice (more than just grounded iron) is good, but most parts are resistant enough not to be damaged unless you do something really dumb, like holding such a part and walk around carpeted areas wearing static-prone shoes while the humidity is very low.

 

[SiBurning]

Or keep the parts loose in those plastic van-der-graff-generator boxes and then grab one and touch it to a grounded iron. Or a grounded you. They actually stand up pretty well to that too. There were rumours in the late 80s that FET ICs and especially MOSFET ICs were seriously prone to static, but they were already pretty good by then.

 

[fishski13]

Quote:

Originally Posted by amb /img/forum/go_quote.gif Proper ESD handling practice (more than just grounded iron) is good, but most parts are resistant enough not to be damaged unless you do something really dumb, like holding such a part and walk around carpeted areas wearing static-prone shoes while the humidity is very low.

carpeted floors and winters in Minnesota. sparks can fly when pulling over the bed covers. i even routinely get shocked when closing the car door after hopping out. i guess i can blame that one on the seat upholstery.

 

[Navyblue]

Humidity here in Singapore is as high as it gets outside of rainforest. And I'm also glad of the fact that the floor at home is tiles on concrete. I am barefooted at home and thanks to the weather we don't wear much clothes here either (no, not naked). It's almost impossible to get shocked here by static outside of air-conditioned room.

I almost decided to get a soldering station yesterday, since I've never seen a grounded soldering iron around here. You guys saved me in time