Bill, Here's a picture of a board that had 14-oz copper layers on layers 2 and 11 that I had to use the airbath on to rework PTH components: http://www.stevezeva.homestead.com/HeavyMetal2.jpg -Steve Gregory- -----Original Message----- From: Steve Gregory Sent: Thursday, January 25, 2007 2:23 PM To: 'TechNet E-Mail Forum'; 'Bill Dworak' Subject: RE: [TN] Assemble question Hi Bill! You need to pre-heat the boards. If they are hand soldering them, one of the pre-heat units that I've used in the past with very good results is from Zephyrtronics...in fact unless I used it, there was no way I could accomplish what I was trying to do. Take a look at: http://www.zeph.com/airbathseries.htm -Steve Gregory- -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Bill Dworak Sent: Thursday, January 25, 2007 2:01 PM To: [log in to unmask] Subject: [TN] Assemble question I am in need of some help with regards to assemble. I am a PCB manufacture and have built a group of boards for one of my accounts and they are having issues assembling and have asked me for help on the issues they are having. The product is 4 layer board power and ground planes with 2 OZ copper inner layers the outer layers are 5 OZ copper. What is happening is that because of the construction of the board it is acting like a big heat sink and this is where the problems are coming from. These are old through hole designs they are assembling them by hand they are heating the irons way up causing surface issues on the boards and in some cases lifting of pads is resulting when extreme heat is applied they are heating them up a lot because of all the copper and as I am being told the solder is not melting the way that it should. Any suggestions to make this a smooth build ? Thank you. Bill Dworak This email is intended solely for use by the individual to which it is addressed and may contain information that is privileged and/or exempt from disclosure under applicable law. It may also contain data subject to the International Traffic in Arms Regulations or Export Administration Regulations and cannot be distributed or copied to foreign nationals, residing in the US or abroad without prior approval of the US Department of State or appropriate export licensing authority. If the reader is not the intended recipient you are hereby notified that any distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify the sender by email or collect call and delete or destroy all copies of this email and/or any files attachments. --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 1.8e 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 -----------------------------------------------------