Hi Jeffrey, Understood - but what is the thickness spec upon receipt - we are seeing +/-.002 variation across a 12 x 18 inch piece. The pieces are right out of the package and are certainly not out of date. Regards Steve -----Original Message----- From: Bush, Jeffrey D. (US SSA) [mailto:[log in to unmask]] Sent: July-15-11 11:47 AM To: Steven Kelly Subject: RE: Pre-preg The thickness will be dependent on what the design is being laminated - planes to planes you yield very close to the pre-preg target - say .003" for a 1080, maybe within 10%, Features will still embed but the fill will maintain the target well. Low-Flow is also problematic to make - the gel-time is modified to reduce the flow window rheology which gives up bond strength and degree of cure. Tg's you will find are reduced - the cosmetic issues are a factor of the poor flow as the glass is not wetting as well as standard material. Excessive striation would indicate to me a resin that is approaching gel-time out of the box and could be old, curing cycle post treat could be off - and even exposure to UV light. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Steven Kelly Sent: Friday, July 15, 2011 11:16 AM To: [log in to unmask] Subject: [TN] Pre-preg Hi All, We are having some issues with lo-flow pre-preg . 1) we are trying to determine from the IPC spec what is the thickness tolerance allowed b) we are seeing a lot of what best can be described as "tiger stripes" throughout the pre-preg. Finally is there an outside lab that can test for resin/glass content that anyone knows. Regards Steve --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------