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IndustryArena Forum > CNC Electronics > Gecko Drives > G201X mosfets not making contact with backing plate
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  1. #1
    Join Date
    Feb 2015
    Posts
    1

    G201X mosfets not making contact with backing plate

    Hi!

    I was about to install my 3 years old but never used G201x in my control cabinet when I discovered that the mosfets on the drive were not making good contact with the hard anodized backing plate. There were visible gaps between TO220 mosfets heatsink and backing plate. I removed the PCB and discovered that the PCB also has slight bend in it. I decided to clean thermal grease that was from the factory and apply new one but can not get the mosfets to sit completely flat on the backing plate. They are glued on the PCB side. H-bridge mosfets make contact about 50% on the side closest to the legs but the side with hole is about 0.3mm raised up. The TO220 package that is mounted closest to the dip switches (voltage regulator maybe?) is the worst - it does not contact the plate at all an has about 0.5mm gap.

    Has anybody had similar issue and if so, how did you solve it.
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  2. #2
    Join Date
    Feb 2007
    Posts
    966

    Re: G201X mosfets not making contact with backing plate

    Get some heat transfer pads and some thermal grease . You can also bend the mosfet away from the pcb a but and put a small cardbourd strip on top so it has more pressure

  3. #3
    Join Date
    Aug 2009
    Posts
    1573

    Re: G201X mosfets not making contact with backing plate

    ...Aluminum Can for shim stock. Remove the Ink and plastic coatings.:cheers:

    DJ

  4. #4
    Join Date
    Mar 2017
    Posts
    411

    Re: G201X mosfets not making contact with backing plate


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