Hi Jack, Lee is absolutely correct to suggest that it is properties that should be specified,not specific base materials—and some people go further than that specifying actual performance requirements. This is a complex situation and still rather in flux. The best that I can suggest at this point is my White Paper [information below] on the subject—and the good thing is that it gets updated as the need arises. Engelmaier Associates, L.C. developed a multi-client study/white paper titled: "WHITE PAPER REPORT: Recommendations for PCB FAB Notes and Specifications in Printed Circuit Board Drawings for SnPb and Lead-Free Soldering Assemblies, the Qualification of PCB Shops and Activities to Assure Continued Quality." As indicated by the title, in this report recommendations are made regarding appropriate specifications and ‘FAB Notes’ on drawings for printed circuit boards (PCBs), general procedures to qualify PCB shops and to assure they would be producing PCBs of good quality, and testing procedures to verify quality and reliability. It contains examples—one for SnPb solder assemblies and one for RoHS-compliant Pb-free solder assemblies—of ‘FAB Notes’ serving as general specifications on PCB drawings being much more specific than IPC-4101B, a ba sic questionnaire for new PCB shops to be qualified meant as a supplement to IPC-1710, as well as recommendations for ongoing activities to assure that qualified PCB shops maintain the quality of the PCBs produced by them. All the recommendations are fully discussed, carefully researched and referenced. Regards, Werner Engelmaier Engelmaier Associates, L.C. Electronic Packaging, Interconnection and Reliability Consulting 7 Jasmine Run Ormond Beach, FL 32174 USA Phone: 386-437-8747, Cell: 386-316-5904 E-mail: [log in to unmask], Website: www.engelmaier.com ************************************** See what's new at http://www.aol.com --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------