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  1. #1
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    Thick rubbery grey filling I'm not familiar with

    Hello guys!

    After several hours of searching I've decided to ask the community about something I'd really like to find out.
    I've disassembled a small electric box (ccfl inverter) to fix some loose wiring, I've noticed that it was filled from top to bottom with a thick grey rubbery compound I've yet to know. I know it probably has to do something with heat, probably some thermal compound.
    My actual question is, what is that grey stuff? The whole pcb and the box was completely filled with it. What is its actual name, and can I use it to fill my project boxes to avoid overheating and also to mask the pcb from those who would open it to copy my work?

    Thanks in advance!

    Robert

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  2. #2
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    Re: Thick rubbery grey filling I'm not familiar with

    If it's elastic, it's most likely silicone rubber encapsulant, like Dow Corning Sylgard 160. If it's rigid, epoxy resin, half-rigid may be polyurethane.


    In case of an inverter, I would expect high voltage insulation as primary purpose. Some encapsulants have also higher thermal conductivity, but they are rather viscose and not well pourable.



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  3. #3
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    Re: Thick rubbery grey filling I'm not familiar with

    Quote Originally Posted by FvM View Post
    If it's elastic, it's most likely silicone rubber encapsulant, like Dow Corning Sylgard 160. If it's rigid, epoxy resin, half-rigid may be polyurethane.


    In case of an inverter, I would expect high voltage insulation as primary purpose. Some encapsulants have also higher thermal conductivity, but they are rather viscose and not well pourable.
    Thank you for your detailed answer, I've searched for the compounds you suggested and found the thing I was looking for!

    Cheers!



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