Hi Karthik, I don't know if this is the most important factor but we have seen in our designs that the clearance on the GND layers above and below the signal traces caused by the via clearances can drastically impact signal integrity. These clearances impact the returning current path on the GND layers and change the characteristic impedance of the signal traces. At high freq this can impact your signal integrity. Thanks, Yoni -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Karthik Raj Guruchandran Sent: Monday, March 08, 2010 7:16 PM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Antipad dimensions Hello all, What would you consider to be the most important factors that would have an impact on antipad clearance dimension (in vias), apart from fabricators capability? In other words, what do we need to consider to determine antipad clearance dimension? I am trying to put together an article on the effect of antipad dimensions on energy transfer (by looking at s-parameters) and see some interesting simulation results. Thanks, Karthik ------------------------------------------------------------------ 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 Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu --------------------------------------------------------------------- Intel Israel (74) Limited This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies. ------------------------------------------------------------------ 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 Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu