The advantage of all one material type is in process yields as well as in supplier management. It's hard to imagine why anyone would mix materials as in your first example. I'd stick with all one type and would never use GETEK. It doesn't have significant advantages and is harder to process. If low loss is important, then use 4000-13SI or IS620. If not, use 4000-13 or FR408. Lee W. Ritchey Speeding Edge P. O. Box 2194 Glen Ellen, CA 95442 Phone- 707-568-3983 FAX- 707-568-3504 I just used the energy it took to be angry to write some blues. Count Basie > [Original Message] > From: Baze, Rick <Rick.Baze@xxxxxxxxxxx> > To: <si-list@xxxxxxxxxxxxx> > Date: 9/7/2004 8:00:24 AM > Subject: [SI-LIST] Board Layer Material Comparison > > A 30-layer board we are in process of designing is under discussion of materials to use and their related advantages and disadvantages. > > The current design has the top 8 layers using N4000-13 for signal/gnd, the next 12 layers using GETEK for power/gnd, and the bottom 10 layers again using N4000-13 for signal/gnd. > > The proposed design is all N4000-13 SI. > > The debate is what advantages/disadvantages there are between the two designs besides the original design requiring longer, more expensive processing. > > Feedback is greatly appreciated. > > Best Regards, > Rick > ------------------------------------------------------------------ > 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 FAQ wiki page is located at: > http://si-list.org/wiki/wiki.pl?Si-List_FAQ > > List technical documents are available at: > http://www.si-list.org > > 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org 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