Hi Grant! I don't know if the boards I've had experience with are like yours, but the ones I've had experience with have had a great deal of copper in them. Below is a cross-section of one: http://www.stevezeva.homestead.com/files/Rough_Cross_Section.jpg The copper core on that one was .055" thick. Here's another: http://www.stevezeva.homestead.com/HeavyMetal.jpg This board didn't have a copper core per-se, but layers 2 and 11 were 40-oz copper layers.. When I first learned that we were going to build the first board I had all kinds of questions. I didn't think our reflow oven was going to be able to handle it. I thought that we were going to need vapor phase to reflow it. But actually, it was a piece of cake. We were using Electrovert Omniflo-10's at the time, and all I really did was slow the belt-speed down to give the board some time to absorb the heat. I normally ran most boards at 32 inches per minute, I ran the heavy metal boards anywhere from 26-28 inches per minute and they did fine. The heavy copper actually made the heat very even across the board, there was very little delta across the assembly. One caution; when a board with that kind of mass comes out of the oven, it is going to be VERY HOT and stay hot for a lot longer than most assemblies! Depending on the mass, the solder on the board may still be liquidous just as it comes out of the oven. -Steve Gregory- -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Grant Emandien Sent: Friday, March 16, 2007 5:42 AM To: [log in to unmask] Subject: [TN] Metal-core PCBs 'netters, has anyone advice/guidelines to offer on the reflow of metal-core PCBs? We are running for the first time and would appreciate any insight. Regards Grant ********************************************************************** Relevant company disclaimers are available at the following addresses: Tellumat (Pty) Ltd e-mail: mailto:[log in to unmask] Web: http://www.tellumat.com/email.aspx ********************************************************************** --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------