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  1. #1
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    Where to buy heat spreaders for ASICs/modules?

    I'm interested in adding a heat spreader to a group of components on a PCB. The components are very fragile so I can't apply pressure to them, even a soft silpad would be too much. My plan is to use a liquid gap filler underneath a heat spreader, but I can't find any vendors that sell them. I'm referring to the sort of lid that is used on CPUs, which mount directly to the PCB with adhesive and have a cavity to accommodate the CPU die. Like in this picture:
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    Any ideas? I need about 1-2mm of clearance, and it has to cover an area of at least 10x10mm.

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    Re: Where to buy heat spreaders for ASICs/modules?

    Hi,

    What about two compound silicon gel?
    It behaves like liquid ... thus it creates no static force to the parts.
    And it behaves like glue and it improves heat transfer.

    Klaus
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    Re: Where to buy heat spreaders for ASICs/modules?

    A silicone gel may work as the gap filler. Main requirements for that are high thermal conductivity, low hardness (like shore 40 or less), and low viscosity. There are tons of fillers to choose from via distributors, but not so with heat spreaders, that's my problem.



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    Re: Where to buy heat spreaders for ASICs/modules?

    Hi,

    Yes, of course the silicon gel is only the gap filler. The silicone gap filler (that I mean ) has no shore value at all. For long term it acts more than a fluid. It is not like the usual silicone.

    ***
    As heat spreader: Maye you could use a aluminum plate or a usual heatsink. There are so many differten ones available.

    Klaus
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    Re: Where to buy heat spreaders for ASICs/modules?

    I imagine your problem is not finding heat spreaders but finding one of those dimensions. I didn't have any luck with the searches I made either. I did come across a product that you may or may not be interested in. Search "diacool - rhp". Probably come with a healthy price tag I imagine.


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    Re: Where to buy heat spreaders for ASICs/modules?

    Quote Originally Posted by KlausST View Post
    Hi,

    Yes, of course the silicon gel is only the gap filler. The silicone gap filler (that I mean ) has no shore value at all. For long term it acts more than a fluid. It is not like the usual silicone.
    Do you have a specific part number I could look at as an example? I always assumed that two-part compounds always cured to become solid.

    As heat spreader: Maye you could use a aluminum plate or a usual heatsink. There are so many differten ones available.
    My goal is to make it so the actual heatsink is not permanently attached to the PCB. Therefore my PCB needs to just have a heat spreader with a flat top that can be pressed against a heatsink. And that pressure can't be translated to the electronics. Again, similar to how CPUs are constructed (nobody wants to buy a CPU with a giant heatsink already fixed to it!).

    Quote Originally Posted by Kajunbee View Post
    I imagine your problem is not finding heat spreaders but finding one of those dimensions.
    Actually I haven't been able to find anyone who sells heat spreaders off the shelf in any form factor. As of now I'm pretty flexible on the size.
    I didn't have any luck with the searches I made either. I did come across a product that you may or may not be interested in. Search "diacool - rhp". Probably come with a healthy price tag I imagine.
    Diamonds are quite a bit more advanced than what I'm going for! And it seems they don't have a catalog of products, only custom designs.

    If I have to go custom I can just have the local machine shop mill me a block of copper or something. But I'd much rather find an off the shelf product, even if it's not a perfect fit.
    Last edited by mtwieg; 4th April 2018 at 19:02.



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