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Need Help for EMI Shielding process

Views: 2084

#37800

Need Help for EMI Shielding process | 10 November, 2005

Hi everybody! I would like to ask some advice which kind of EMI shielding process is easy to use, economical and at the same time efficient. I've been doing research for different kinds of shielding process to be used in our product. Can anybody give advice on your experiences?

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#37809

Need Help for EMI Shielding process | 11 November, 2005

What type of product [eg, board, enclosure, etc] are we talking about?

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URL

#37813

Need Help for EMI Shielding process | 11 November, 2005

EMI shields are no fun! Your process will depend on your design and condition of the shields. We always break the shields into their own process. Because the shields are never flat, screen printing paste and trying to reflow them only caused huge coplanerity issues. We are forced to keep the stencil thickness at 6 mils due to the fine pitch devises. The only option left was adding paste for the shields manually and hand placing them. I guess an X-Y table would work if a cost justifiable.

If I had my way, I would use surface mount clips designed for shields or use the thru-hole clips.. This may not provide enough EMI depending on your design. Two piece shields should also be considered; the ones with the removable tops. This makes SMD repair a lot easier as well as inspection to the soldering of the shields.

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Rob

#37814

Need Help for EMI Shielding process | 11 November, 2005

Hi,

There are 2 main steps to reducing EMI from a product.

The first is to minimise it at source with smart design (keeping signal traces short, lots of decoupling etc). There should be design guides available from internet seach engines. Many manufacturers of inductors & ferrites have software which allows you to select the right component to reduce different types of noise.

The second is to trap it inside, via a metal enclosure if possible (faraday cage), and filtered connectors (such as filtered D-types, inductors & decoupling caps on out puts, ferrite beads, cores clamped around wires etc).

What sort of product is it?

Rob.

For further inspiration visit http://www.pilsner-urquell.com

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#37818

Need Help for EMI Shielding process | 11 November, 2005

Rob: After SAB purchased Pilsner Urquell, they changed from using hops to a extract of hops in their process. They changed the foil on the neck of the bottle from silver to gold at the same time. The result was PU went from THE UNDISPUTED BEST beer in the world to just another very good beer. I spoke with Vojtech Homolka, the Export Quality Manager at PE, shortly after the change. He said, he hadn't noticed any difference. The folk at Beer Advocate [ http://beeradvocate.com/ ] sure notice the change, also.

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Rob

#37820

Need Help for EMI Shielding process | 11 November, 2005

Thanks Dave,

I thought it tasted different - I just put it down to having not travelled well.

I'm off to find some Trappist Westvleteren 12.

I would ask if there is anything you don't know, but I don't want my illusions (or delusions!) of your omnipotence shattered!

Cheers,

Rob.

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#37821

Need Help for EMI Shielding process | 11 November, 2005

I'm trying to learn to speak Spanish.

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Rob

#37823

Need Help for EMI Shielding process | 11 November, 2005

Hola Dave y le agradece por toda su ayuda.

Michel Thomas is great - Appologies to the Spanish speaking contingent if that makes no sense.

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#37826

Need Help for EMI Shielding process | 11 November, 2005

Thanks for the reply everybody!!! It is a compact RF device it is currently being designed our R&D is asking some suggestions what kind of shielding would be best for it. It is quite compact that we will be using 0201 chips on it. Anybody have experience with a snap on ball EMI shielding?

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