Earl, I used the Heller four zone oven (thinks its a five) to float .190 inch thick 16 layer (double sided SM) with an active .060 thick CIC slab in the center. The oven worked great. By the way I used the RF SuperMole on each run and used a fairly large sheet steel fixture... talk about thermal profiling! This was all compliant to the MIL-STD-2000 spec and a tough QA group. Later a larger volume went through the Conceptronic oven without incident. [Success was a function of dummy parts and teaming process controls... hence its not all the oven.] Major reason for the fixture: boards got very heavy after a few of them... Coretec's Boston Brad --------------------------------------------------------------------------------- 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 e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest 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 ---------------------------------------------------------------------------------