On Wednesday, July 10, 1996 7:07 PM, Walker,   
Don[SMTP:[log in to unmask]] wrote:
>There is absolutly no generic reason I can think of why a plane should
>not extend under the gold edge card fingers.  I have done it for years
>with no problem at all.  Especially if you are working on EMI critical
>designs you would not want to have a big hole in your shielding created
>by removing the planes from an area of the board.
>
>Don Walker
>Austron Inc.
>[log in to unmask]
>

One thing to remember about internal planes and edge card fingers is that   
you should make sure to pull the planes away from the edge enough to   
allow for the beveling w/ tolerances and minimum copper to edge spacing   
requirements.  This could be where the reasoning for removing planes   
under fingers came from - someone got 'bit' with exposed copper plane   
after beveling, so they deemed it better to remove all planes under   
fingers (this is just a guess on my part).

We usually try to pull the plane back .100 inch from the edge along the   
fingers.  Our reasoning to maintain the planes under fingers is the same   
as Don's - we need to avoid any EMI problems.

Just a thought......
Ben
[log in to unmask]

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