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What's that smell? — Parallax Forums

What's that smell?

ElectricAyeElectricAye Posts: 4,561
edited 2010-04-03 06:00 in General Discussion
Okay, I know this might seem like a dumb question but I'm curious because I'd like to know what sort of trace chemicals are wafting around in my lab during experiments: What exactly is the source of that smell you detect when electronic things are getting hot? Is it the fumes from a polymer inside the PCB board material itself? Is it some kind of chemical used in soldering? something inside capacitors that is starting to vaporize? random microscopic flakes of human skin turning slowly to smoke? It seems universal, ubiquitous, and (thanks to my special skills) occurs all too often. Anybody happen to know?

smile.gif

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2010-04-02 03:34
    I suspect it's the epoxy used to encapsulate most components these days. The PCB material is mostly epoxy itself, but it won't get too hot until the various components get hot first.

    Resistors and ceramic capacitors use ceramic for a substrate with various conductors / carbon materials deposited on them all of which are pretty temperature resistant. Electrolytic capacitors do have an electrolyte that could be vaporized, but there aren't as many of those on any given PCB. Resistors and active components (transistors, diodes, ICs) are what would normally get hot first.

    Any flux from soldering should have been washed off any commercial boards. Solder mask and other paint for markings would still be present, but wouldn't normally get too hot.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2010-04-02 03:36
    Probably phenol, and maybe some formaldehyde, from the outgassing polymers.

    -Phil
  • ElectricAyeElectricAye Posts: 4,561
    edited 2010-04-02 14:55
    Thanks, guys. I'm amazed that no matter how many times I overheat things, they keep on emitting that same smell. Either humans are very sensitive to it or there's a little worm hole doorway inside each and every chip and there's just no way to stop the stuff from coming through some other dimension.

    And I wonder: once we all start donning wearable electronics, will the entire human race end up smelling like that? lol.gif
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2010-04-02 15:49
    ElectricAye said...
    And I wonder: once we all start donning wearable electronics, will the entire human race end up smelling like that?
    Yes, but just think how warm we'll all be!

    -Phil
  • lardomlardom Posts: 1,659
    edited 2010-04-02 16:49
    I sit here amazed at how much knowledge is here.

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  • ElectricAyeElectricAye Posts: 4,561
    edited 2010-04-02 16:57
    lardom said...
    I sit here amazed at how much knowledge is here.


    Lardom, and I sit here wondering what your icon is a picture of. A porta-potty from outside the Pollux star system?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Watching the world pass me by, one photon at a time.
  • John R.John R. Posts: 1,376
    edited 2010-04-02 20:21
    You guys are just no fun.

    Here I've been working under the assumption that the aroma/odor is either:

    A) Gods way of telling us we have an "oops".

    or

    B) An additive added to the components, similar to the additive in natural gas, to alert you to a potential problem before there is a fire.


    All this stuff about epoxy, phenol, formaldehyde, out-gassing, etc. just plain takes all the fun out of it.

    Please, PLEASE, don't any ask about the Easter Bunny...

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    John R.
    Click here to see my Nomad Build Log
  • WhitWhit Posts: 4,191
    edited 2010-04-02 20:30
    All I know is that I like the smell of a new board warming up! Smells like fun!

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    Whit+


    "We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2010-04-02 20:33
    ElectricAye said...


    And I wonder: once we all start donning wearable electronics, will the entire human race end up smelling like that? lol.gif

    To attraction for "geek" chics. Could work like aftershave...

    As for the smell.. Sorry, had mexican for lunch.. [noparse]:)[/noparse]

    OBC

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    Visit the: PROPELLERPOWERED SIG forum kindly hosted by Savage Circuits.
  • WhitWhit Posts: 4,191
    edited 2010-04-02 20:42
    Oldbitcollector said...

    As for the smell.. Sorry, had mexican for lunch.. [noparse]:)[/noparse]

    We'll just start calling you Oldbeancollector...

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    Whit+


    "We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
  • ElectricAyeElectricAye Posts: 4,561
    edited 2010-04-02 20:49
    Whit said...
    All I know is that I like the smell of a new board warming up! Smells like fun!

    Whit,

    you wouldn't happen to be related to this guy, would you?

    www.youtube.com/watch?v=bPXVGQnJm0w
  • ElectricAyeElectricAye Posts: 4,561
    edited 2010-04-02 20:53
    John R. said...
    ....

    Please, PLEASE, don't any ask about the Easter Bunny...

    Well, I've been heating him for hours over one of my power circuits and so far.... just smells like singeing fur.
  • DufferDuffer Posts: 374
    edited 2010-04-02 23:27
    I think lardom's avatar is from the game, Myst.

    Duffer

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Any technology, sufficiently developed, is indistinguishable from magic.· A.C. Clark(RIP)
  • John R.John R. Posts: 1,376
    edited 2010-04-03 00:16
    ElectricAye said...
    John R. said...
    ....

    Please, PLEASE, don't any ask about the Easter Bunny...

    Well, I've been heating him for hours over one of my power circuits and so far.... just smells like singeing fur.

    As long as he's real, I'm OK with that... He'll be able to do his magic to get out in time to delivery my basket of goodies!

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    John R.
    Click here to see my Nomad Build Log
  • icepuckicepuck Posts: 466
    edited 2010-04-03 01:20
    John R. said...


    Please, PLEASE, don't any ask about the Easter Bunny...

    How 'bout the Ether Bunny?
    -dan

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Arguing with myself--sometimes me, myself, and I don't always agree.
    (Former) Caterpillar product support technician
  • ElectricAyeElectricAye Posts: 4,561
    edited 2010-04-03 01:35
    icepuck said...


    How 'bout the Ether Bunny?
    -dan

    That has been proved to be entirely fictitious.
    en.wikipedia.org/wiki/Michelson–Morley_experiment

    lol.gif
  • ercoerco Posts: 20,261
    edited 2010-04-03 03:01
    I can trust you guys with my aphrodisiac cologne secret: 50% rosin and 50% heat sink compound. A dab behind each ear and the ladies melt like 60/40 solder.

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    ·"If you build it, they will come."
  • lardomlardom Posts: 1,659
    edited 2010-04-03 06:00
    @ElectricAye, @Duffer My avatar is from the MYST series of pc games. I PhotoShopped myself into it years ago. The realism was incredible and the graphic I chose was 'no doubt about·it' fantasy. I was starting to wonder if anybody was curious about it.
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