Basically the geometry of the BGA package is the same for the leaded and lead-free versions; the BGA pitch and the grid array are the same too: that's why I presume that the capacitance C_pkg is the same. The only difference is the metal alloy used for the solder-balls: that's why I suppose the resistance R_pkg is quite different and that causes an impedance mismatching, which is critical specially for high-speed interfaces. What about L_pkg? Any suggestions? It is true that *normally* vendors use simulators, but at the end of the day it is quite hard to get *reliable* IBIS models from them: just have a look to the disclamers included into IBIS models or check the warnings/errors that you get when validating an IBIS model with a golden parser... Giulio -----Messaggio originale----- Da: giancarlo guida [mailto:gguida@xxxxxxxxxx]=20 Inviato: marted=EC 13 luglio 2004 10.46 A: giulio.tamberi@xxxxxxxxxxxx Oggetto: Re: [SI-LIST] IBIS models for Pb-free (lead-free) BGA package Hi Giulio, surely if package change all its parasitic value should change. Normally package vendor use simulators to calculate the parasitic parametrs of diufferenbt kind of packages. Giancarlo ----- Original Message -----=20 From: "Giulio Tamberi" <giulio.tamberi@xxxxxxxxxxxx> To: <si-list@xxxxxxxxxxxxx> Sent: Tuesday, July 13, 2004 12:29 AM Subject: [SI-LIST] IBIS models for Pb-free (lead-free) BGA package Hi, =20 I have got reliable models of memories and processors provided in BGA packages. I use those models for signal-integrity simulations and I am quite confident of the positive results that I have got so far. Hoever, because of new European standard, most of digital components that I was using are now available into Pb-free (lead-free) BGA package, while the internal chips stay the same: any suggestions about possible changes into their IBIS models? From my point of view al least the R_pkg should be different... What about C_pkg and L_pkg? It looks that most of IC's vendors are providing the same IBIS models for both the leaded and lead-free versions. Any comments? =20 Thanks, Giulio ------------------------------------------------------------------ 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: =20 //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