Michael, Your very eloquent answer probably is quite correct. However, how many of us work in an uncured or over cured world. I know the question was stated as the difference between cured and uncured, but how can we make boards with less or more cure that are acceptable as specified. Out of the window is out of spec, right? Having worked with very low dielectric constant materials (styrafoam as an example), approximating air, I know it is not practical to attempt, at this time, building circuitry with such materials. My answers to the initial question were based on what is required to make a circuit practical in terms of manufacturability, acceptance, and performance. I realize you folks at Merix are on the cutting edge. If you could share a bit of your future plans, based on your excellent answer to the original question concerning degree of cure, we would all appreciate this. Respectfully, Earl Moon --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------