I think the venting that was mentioned in an earlier reply was from someone who thought my responses were venting frustration with a bad practice in PCBs. yes, it could be called venting, except for teh CAD departments who have to try to make Gerber files that include this type of plane structure. I don't know what the venting being discussed in this latest string of mail referes to. For those who saw my response as simple venting, I apologize. For all those engineers and designers who have been asked to create cross hatched planes, maybe this helped. For the record, the only fab shops I have seen ask for this in the last five years are located in Southeast Asia. Wonder why they do that? Lee Ritchey > [Original Message] > From: Jeff Seeger <jseeger@xxxxxxxxxxxxxx> > To: <si-list@xxxxxxxxxxxxx> > Date: 4/5/2007 12:35:30 PM > Subject: [SI-LIST] Re: Cross-hatched reference planes > > Andy wrote: > > > what is "venting"? > > In built-up multilayers, which start with a traditional core > laminate, subsequent dielectrics are applied in liquid or semi- > liquid state. Unbroken copper areas inhibit cure. Relief is > in the form of "vent" pads appearing as stray anti-pads, or as > a cross-hatch shape. > > Sorry that carpal tunnel limits my replies. Or maybe that's a > good thing. > > Best regards, > > -- > > 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 > ------------------------------------------------------------------ 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