IS415, a 200°C Tg product, is Pb-free compatible and offers improved signal integrity performance. Now has electrical loss in the 0.009 range using the split post resonant cavity method, and around 0.0135 using the Bereskin Stripline test method at 10 GHz.  Currently available in North America, with manufacturing in Asia to begin in 2007.  Is RoHS compliant and a UL94V-0-rated substrate.
 
Isola Group, www.isola-group.com