EMI Suppression Advice

[kiddsm95]

Hi,

I'm working on an enclosure that's operating at 8 Gig to 20 Gig frequencies, and we're having difficulties in the higher frequency ranges. We've used steel EMI spring products, fabric over foam, etc... and we're now looking at board level shielding devices, only catch is that there must be integrated heat sinks due to thermals. Anyone have experience with this? There are a few companies out there that offer cans that go over BGA's, but none that have integrated heat sinks. Is there a process that exists where we could possible spray a coat of conductive mat'l over the PCB?

Any advice will be appreciated.

Thanks.

 

[apdesign]

What problem are you having at higher freq. ranges? What compliance test are you trying to pass that makes a traditional faraday cage impossible?

My own experience with ~10 GHz clock signals has been that the only method that works is to take the heat out through copper llayers/thermal vias in the PCB or a slug heat sink on the solder side of the board.



Tyler Cox
Principal
Applied Product Design, LLC
Westtown, NY 10998

 

[nigelt]

We have done custom shield/heatsink using die-cut compliant thermal pads over BGA devices. Your production volumes would suggest the means of production for the shield/sink, but machining of alum is an option. Question will be how you need to attach the box to your pcb, if screws are not acceptable

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