[SI-LIST] Re: Cross-hatched reference planes
- From: Jeff Seeger <jseeger@xxxxxxxxxxxxxx>
- To: leeritchey@xxxxxxxxxxxxx
- Date: Wed, 04 Apr 2007 11:27:05 -0400
Lee Ritchey wrote:
>All of those reasons, except the flex circuit one, went by the wayside many
>years ago. Wonder why they still linger around the industry like old socks!
>
Agreed venting and bonding concerns first appeared in 60s military
specs but I'll wager that if you were to chat up a substrate foundry
there is current call for venting.
On the bonding front we were recently asked to provide some "hatch",
understood to be for laminate to laminate, in an area of a board
lacking vias. The board involved fussy materials and a challenging
end-use environment. I don't believe it was an offhanded request.
We'll simply have to agree to disagree on cross hatching as a way
to work with supply- and signal- dense areas to minimize the layer
count *and* bow and twist.
I'd be happy to debate further but suggest IPC's Technet as a more
appropriate forum for the bandwidth on DFM issues. Old socks can
become new again, it can be useful to recall where we put them.
Respectfully,
--
Jeff Seeger Applied CAD Knowledge Inc
Chief Technical Officer Tyngsboro, MA 01879
jseeger "at" appliedcad "dot" com 978 649 9800
------------------------------------------------------------------
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 technical documents are available at:
http://www.si-list.net
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:
