Phil, all You are on the right track with testing for blistering/delamination at LF assembly as an indicator of a material's capability to withstand LF processing. You should keep in mind however that: a material could pass your test, but if you have that material fabb'ed by a different PCB fabricator you could get a different result; AND, if you have the material fabb'ed into a different board (more layers; thicker) you could get a different result, AND if you have the same part fabb'ed by the same PCB supplier fabb'ed again from a different lot of material - guess what? - you could get a different result. This is a huge problem. If a material can't pass muster initially, then it isn't LF capable; but even if it does pass muster, we must still maintain vigilance. It will likely be awhile before these materials and the methods to turn them into multilayers settle down into anything close to the predictability we have had with the current batch of materials at the old reflow temperatures .... Valerie Phil Nutting <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 12/13/2005 09:32 AM Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to Phil Nutting <[log in to unmask]> To [log in to unmask] cc Subject Re: [TN] Qualification of the Pb-free capable manufacturers Charlie and Werner, Our current solution is to fab a group of test boards all at the same time, but using several different laminate materials from different vendors. We will then run them through a temperature torture test at the same time. Example; 3 Tg 170 board materials processed together, then run through wave together. We will be watching for blistering and delaminating. Phil --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 -----------------------------------------------------