I am using bare die (bumped flip chip) in a SIP application utilizing solder attachment to the substrate. I need to modify the package pin parasitic parameters in the representative IBIS models. What should I use if anything for the package pin patristic parameters for this type of attachment? I did find a document that described a model which could be used for ACF attachment, but do not know if the results would be the same for solder attachment. The document is titled "High-Frequency SPICE Model of Anisotropic Conductive Film Flip-Chip Interconnections Based on a Genetic Algorithm" and appeared in the IEEE TRANSACTIONS ON COMPONENTS AND PACKAGING TECHNOLOGIES, VOL. 23, NO. 3, SEPTEMBER 2000. best regards, David Tate Lockheed Martin Missiles and Fire Control Senior Staff Circuit Design Engineer Electrical Engineering - FPGA/Processor Design E-Mail: david.tate@xxxxxxxx ------------------------------------------------------------------ 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