Electrical Conductive Adhesive?

Discussion in 'Tonefreaks' started by Platte City Paul, Dec 20, 2017.

  1. Platte City Paul

    Platte City Paul Senior Member

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    Folks,

    I managed to break a component off of the PCB board of a pedal I have. I don't know whether it's a cap or a resistor or whatever.

    What I do know is that it wasn't soldered through the PCB. The pins don't come straight out of the component through the board to be soldered on the other side like most are.

    The pins coming out of the component look more like tabs, and are bent 90 degrees. In other words, they'd sit flush on the board instead of going through the board to receive solder. (I'm at work so no pics.)

    If that all makes sense, what I want to try and do is use some kind of adhesive to put the component back on the board. Soldering would not work here. (I don't think the component was soldered in the first place.)

    I understand there is electrically conductive adhesives out there. Anyone have experience using these? Any suggested brands and tips appreciated.

    The component itself is small - maybe a quarter the size of a pencil eraser for those old enough to remember pencils and erasers. :p
     
  2. ARandall

    ARandall Senior Member

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    Might be worth a pic of component and place it broke from
     
  3. Platte City Paul

    Platte City Paul Senior Member

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    Yessir. I will do that when I get home from work.
     
  4. Jymbopalyse

    Jymbopalyse Senior Member

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    Heatsink perhaps
     
  5. Platte City Paul

    Platte City Paul Senior Member

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    Pics. Under magnification, it does look like the two leads have solder on top. Maybe I'll try that first. I have a low wattage iron with a really narrow point.

    The component goes in there the two rectangular spaces next to C16 are on the board.

    [​IMG] [​IMG] [​IMG]
     
  6. ARandall

    ARandall Senior Member

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    It does look like its been soldered though....if its those 2 oval pads I'm supposed to be looking at.
     
  7. spitfire

    spitfire Senior Member

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    First off, this is what is called a surface mount device (SMD). That's the proper term for these type of components that don't go thru the PCB.

    It was soldered and the pads that were on the board are now on the capacitor that broke off. There are no pads on the PCB anymore, the PCB has been damaged.
    Soldering is the way to fix this. But you'll need to get solder from the legs of the capacitor to the via's (holes) you see that are near those pads. That's where the pads were originally connected.

    That grid you see around the pads is ground plane. Be sure NOT to solder to that. It's covered in solder mask, so solder won't want to stick to it, but it will if you rub your soldering iron on it and melt through the solder mask.

    The pads are so close to those holes, you can probably just create a solder bridge (blob of solder). But if that is difficult, solder a small wire in the holes, bend the wire over and solder to the legs of the cap.

    The pads are what holds the component to the board, and those are no longer attached to the board, and the repaired solder connections might not be that strong. So I'd consider gluing the component to the board before soldering. CA (super glue) is good for this. Just a very small drop on the board is all you need. Just don't get glue on the part you want to solder. You could also solder first, and then put a glue around the base of the cap to glue it to the board.
     
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  8. Platte City Paul

    Platte City Paul Senior Member

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    Hey, thanks, Spitfire. All useful. That's probably beyond my skill level, but I'm still game to try. If I screw it up, the worst I have is a non-functioning delay pedal, just like I have now.
     
  9. Platte City Paul

    Platte City Paul Senior Member

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    Check this out...

     
  10. spitfire

    spitfire Senior Member

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    While interesting, I can't see why you you would ever use something like that. It looks to make the job 10X more complex than just soldering down a new part. Mixing the adhesive, and then letting it cure for a day seems pretty inconvenient. I also don't like the way he says to "chop out the old part". If care is not taken removing parts, it's very easy to break off pads and traces. Now, it can be tricky to un-solder any part where to get the part off, you need to un-solder multiply pins or legs. So sometimes cutting pins is needed if you don't have professional equipment (hot air is what is used).

    And I find it odd that when the job is done, clearly there is conductive adhesive connecting at least two of the three pins of the device in the video. If that stuff is conductive, that would not work.

    Anyway, I'm not trying to blast the suggestion, I'm just having a hard time seeing the value in this. It seem more marketed to people who are just inexperienced and afraid to work on circuit cards. All you really need is a decent, temperature controlled soldering iron. Which if you are attempting to do any work with electronics, you should own one anyway.
     
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  11. Platte City Paul

    Platte City Paul Senior Member

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    Agreed all. There was another video where an individual used a hot air blower. That looked to be a better option than cutting the component out.
     
  12. RicOkc

    RicOkc Senior Member

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    OK....I worked in the electronics manufacturing business for longer than I want to admit, and SMT was in the equation and micro soldering.

    Put a small dab of (non conductive) silicone on the end of a toothpick, apply it to the component, stick it on the board and solder it. Using any sort of glue on a board will cause you nothing but problems if you have to do any further repairs.

    For removal, using solder wick, a pair of tweezers and a soldering iron is all you need. Also a steady hand!

    A hot air blower would help, but how many people here have access to one?
     
  13. Leña_Costoso

    Leña_Costoso Senior Member

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    How about just get an radial lead capacitor and use those thru-hole plated holes to affix, and be done with it.

    1 50 G11 , not sure on SMD components but 1 would be a 10x multiplier, 50 the value, G the voltage 4volts, and the 11 is the temperature code? Someone with more of a clue for SMD components could be of use!

    Before I'd jump thru all sort of hoops tho, I'd solder leads into the holes, then heat sink each one and solder it to the component. Trying it the other way round is gonna be an attempt at futility.
     
  14. DarrellV

    DarrellV About as sharp as a bowlin' ball! Silver Supporter Premium Member

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    No one has mentioned the polarity of the cap yet, so I'm gonna jump in here and suggest that OP make sure he attaches it the right way.

    Looks like the black side is negative and the silver side faces positive on all the other ones on the board...
     

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