Werner, The sample I have from our sister company does not have metal surrounded by 2 pcbs. It is a real metal pcb that is intended to act as a heat sink for the leds and is not surrounded by any FR-4. (Yep, a soldering nightmare that I am sure plenty of assembly personel will be happy to work on...) It is just a piece of aluminum that has a coating on one side with traces laid on top of that followed by a soldermask. We will not be putting the leds on ourselves, but will look for a cm to assemble it. I believe that our sister company may have a CM that is hand soldering the leds to the mcpcb. The only other part that goes on this is a connector that will connect a FR-4 pcb to drive the leds. As for your White Paper, I have not read it as our pcbs are typically all through hole and our engineers are just now in the process of converting to RoHS compliance. Nila -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Werner Engelmaier Sent: Thursday, June 14, 2007 4:18 PM To: [log in to unmask] Subject: Re: [TN] MCPCB finish questions Hi Nila, Your PCB sounds like a "challenge"-not to say nightmare in this brave new LF-world of ours. I sure hope you are planning on using vapor phase for your solder assembly process, otherwise the thermal requirements are going to be "hellish". When you say 'metal core', do you mean a real metal-core substrate, or a PCB with a heat sink in the middle surrounded by 2 FR-4 PCBs? What are you doing to make your PCB survive the LF-assembly process? Did you read my White Paper on the subject? Werner ************************************** See what's free at http://www.aol.com. --------------------------------------------------- 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 -----------------------------------------------------