[SI-LIST] Re: Copper Thieving
- From: Robert Haller <rhaller@xxxxxxxxxx>
- To: williamm@xxxxxxx
- Date: Tue, 13 May 2003 17:01:52 -0400
Bill,
Large solid copper area's are usually frowned upon. Manufacturing
usually prefers a cross hatched pattern. A large copper area will plate
unevenly and negatively impacts current density.
A multilayer design should be able to accommodate manufacturing needs in
conjunction with electrical requirements.
Some design houses do use copper thieving on inner signal layers to
better control the copper etching process. But if you are using a dual
strip line configuration for your stack up you need to be particularly
careful about any signal integrity impact on adjacent signal layers.
Inner planes generally are already mostly copper,dimensions are not as
critical, and manufacturing modifications could be catastrophic to
signal return paths.
regards,
bob
Bill Mueller wrote:
> Hello again all,
>
> It's nice to have a name to it. Thanks for all the
> great information.
>
> My buddy and I here usually fill large open areas
> with solid planes stapled to the nearest power/ground
> plane. Pretty much to add another reference to signals
> on adjacent layers.
>
> So two more questions come to mind:
>
> 1. If we started making many-layered boards (8-10+),
> would these manufacturing considerations begin
> to out-weigh the electrical benifits?
>
> 2. Is copper thieving used on internal layers?
>
> Thanks again,
> -Bill
--
Robert J. Haller (rhaller@xxxxxxxxxx)
Principal Consultant
Signal Integrity Software Inc.
6 Clock Tower Place, Suite 250
Maynard, MA 01754
Phone: (978) 461-0449, ext 15
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
- » [SI-LIST] Re: Copper Thieving
