Dear listl, How prepreg layers effect the impedance of a stripline? To clarify, my stack-up is; S1 -------------- core -------------- GND -------------- prepreg -------------- S2 -------------- core -------------- VDD1 -------------- prepreg -------------- S3 -------------- core -------------- GND -------------- prepreg -------------- S4 -------------- core -------------- VDD2 -------------- prepreg -------------- GND -------------- core -------------- S5 We assume that pcb cores are hard enough to achieve the required line impedances. But, how about the impedances for the striplines with one core and one prepreg layer as neighbours, such as GND-S2-VDD1. Is there a rate of deviation after pcb manufacturing due to prepreg shrinking? Is not it more problematic if we have multiple core and prepreg layers? Any comments, suggestions? Thank you. Cengiz Aydin Researcher Bilkent University ------------------------------------------------------------------ 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