Michael: I have only one data point. Taiyo PSR-4000BN photoimageable soldermask has a loss tangent of 0.0009 (no freq specified...), or so I have been told. However, I did notice that Johnson's new book (High speed signal propagation) lists Er and tan-d values for several soldermask materials (see page 280). Hope this helps. Regards, jf -----Original Message----- From: Chan, Michael (Eng Hou) [mailto:Michael.Chan@xxxxxx] Sent: Thursday, March 06, 2003 11:23 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Loss Tangent of Solder Mask Hi: Anybody has any idea what is the loss tangent of solder mask? Thanks. Regards, Michael Chan H-P Corp. ------------------------------------------------------------------ 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: http://www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: http://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: http://www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: http://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