Desoldering using griddle

Discussion in 'General Electronics Chat' started by Razor Concepts, Feb 15, 2010.

  1. Razor Concepts

    Thread Starter Active Member

    Oct 7, 2008
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    You can solder with an electric griddle, so I suppose you could desolder an IC with a griddle also? After it is heated up, use something (tape on a stick) to lift the IC out? If it helps, the solder holding the IC down is leaded. Thanks!
     
  2. retched

    AAC Fanatic!

    Dec 5, 2009
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    You may want to consider a heat gun.

    Using a griddle, you may spend too much time trying to soften the solder. The heat gun works great. I use it for de-soldering to salvage off old boards. As long as the griddle gets above melting temperature, it should work, however there is alot of heat going other places besides the chip you want it on.

    I have never tried the griddle method.

    For pulling IC's I use a pair of small channel locks that I plasti-dipped the jaws. You can also slide the rubber handle covers off an inch, cut them off and pull them over the jaws.
     
  3. PackratKing

    Well-Known Member

    Jul 13, 2008
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    OK now I'm confuzzed :confused: I was under the impression that excessive heat, such as either method mentioned would ruin Ic's, especially CMOS varieties, and others sensitive to static and the like ..........What of the magnetic field set up in the griddle heat coil ??

    To salvage useable components, I place a small heatsink on leads, melt the joint with an appropriate soldering iron and blow the solder away w/ low pressure air, which in turn immediately cools the lead. Special box constructed to catch all solder blown in one direction.
     
    Last edited: Feb 20, 2010
  4. russ_hensel

    Well-Known Member

    Jan 11, 2009
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  5. BMorse

    Senior Member

    Sep 26, 2009
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    I would go with the heat gun technique more so than a blow torch!! Atleast with a heat gun you can slowly heat the board until the solder melts.....

    What I usually do is heat the PCB with the component I want to remove with a heatgun from the solder side..... once the solder melts, I tap the PCB onto my benchtop and the components fall right off. You can slowly heat the PCB and give it a tap to see if the solder has melted enough for the components to come off, this way you would be less likely to overheat the component. I use this technique in salvaging through hole components and surface mount components, and also for board repairs...

    My .02
     
  6. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    Does this work well for high pin DIP? I have a number of 40 pin dip sockets I can salvage.
     
  7. Razor Concepts

    Thread Starter Active Member

    Oct 7, 2008
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    Thanks for the help! I am actually not salvaging the IC, but replacing it since it fried. Also the board has little other important ICs so I may just have to try the griddle method anyways.
     
  8. t06afre

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    May 11, 2009
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    Last edited: Feb 15, 2010
  9. BMorse

    Senior Member

    Sep 26, 2009
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    this could work on some dip sockets, some tend to melt at a lower temp than the solder, but I have manged to salvage all sorts of components this way, connectors, IC's, passive components, etc....
     
  10. t06afre

    AAC Fanatic!

    May 11, 2009
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    I have found out then dealing with large chips, and doing rework/salvaging. It is always smart to have an extra hand when working with the hot air method
     
  11. maxpower097

    Well-Known Member

    Feb 20, 2009
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    Rather then using direct heat with a griddle, I think you'd be better off modding a toaster over into a half azzed reflow. Then your idea should work fine.
     
  12. Razor Concepts

    Thread Starter Active Member

    Oct 7, 2008
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    Stove = concentrated heat = too much heat :)

    Here is what happened, I think the stove was too hot.

    A few months ago I fried my axon by static discharge; I was trying to use a 16x2 LCD. So now it is time to start the repair process!

    Axon to be desoldered, washer for heat transfer:
    [​IMG]



    Washer on stove, heating up:
    [​IMG]


    Testing temperature with leaded solder (I have leaded axon).
    Solder melts, time to put axon on washer.
    [​IMG]


    Hypersonic-suction IC remover device successfully extracts mega640, the 16mhz crystal felt like coming, too
    [​IMG]


    Melted soldermask due to the heat:
    [​IMG]



    Next up is to determine the damage to the underside and see if it is still worth it to fix. Luckily there only appears to be two small traces that might be affected, the majority of the burns are on the power/ground planes.
     
  13. retched

    AAC Fanatic!

    Dec 5, 2009
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    Ouch. Hot air is the way to go. You said you didnt want to salvage the chip, I alo figured you didn't want to salvage the PCB.

    For future, get yourself a $15us heat gun from HarbFreigt. It has a low at 122-570deg setting that is ideal for this. You can also use or make a narrow tip for the gun that allows for better directing of heat. Also, hot air is better than hot solids. Solids absorb more heat from other solids. Thats why heat sinks work. Using the air, you will do less damage. Imagine taking a 300deg piece of steel and sticking it in your hair, It would fry it. But if you blow 300deg air in your hair, it drys it.
     
  14. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    Bless you my brother!! I just picked up a heat gun at Harbor Freight. Turns out it was a sale item this month. I snagged it for $10.

    Anyway I tried it out and wow!!!! Is it easy to desolder!
     
  15. retched

    AAC Fanatic!

    Dec 5, 2009
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    I tell ya.. Sliced bread..
     
  16. Razor Concepts

    Thread Starter Active Member

    Oct 7, 2008
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    Well, surprisingly none of the traces are broken, so I will buy a mega640/1280 and it should be good to go!

    Too bad I don't have a harbor freight in my area, they have tons of good deals all the time...
     
  17. retched

    AAC Fanatic!

    Dec 5, 2009
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    That is one resilient PCB! A new chip and some clear fingernail polish, and your set.
     
  18. Metalfan1185

    Active Member

    Sep 12, 2008
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    I got one from harbor frieght! Mine cost $20 though....:rolleyes:

    one thing that i did for this type of thing was I made few square pieces of metal and formed them to the size of the chip (kinda looked like a cookie cutter) and placed it around the pins to isolate (most) of the heat from reaching things other than the chips.

    after that was on there i made another nozzle for the gun to focus the hot air to aim it into the 'cookie cutter' lol.

    But I got rid of them recently because my work threw out a hot air reflow station that was broken, so a few secured intermittent connections later...Its a weller something...big blue thing.

    I still keep the heat gun...works great for pulling those heatsinks off of boards where they solder the heatsink on and it takes forever to heat it with an iron.
     
  19. Wendy

    Moderator

    Mar 24, 2008
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    I've used high temp hot plates to assist with soldering. Basically you use the plate to decrease the temperature differential, so you can leave the iron on the part for substantially less time. It is also useful for hot air desoldering stations. It also decreases the odds of a cold solder joint substantially, since the solder cools at a much slower rate.

    I'm not too sure about what I'm seeing though, it is also important to inject the heat uniformly. Solder melts at 212°C (414°F) give or take a few degrees, I used a hot plate set for 200°C (392°F). I have also used hot plates as cool as 150°C (302°F), every little bit helps.
     
  20. maxpower097

    Well-Known Member

    Feb 20, 2009
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    I'm about to do some de-soldering too. With the heat gun method what are the odds of making popcorn out of my ic's? Also how big of an output does the heatgun have? Can I only heat up a half inch squared?
     
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